Senior Software Engineer Interview Questions and Answers

To become a software engineer as a career option, you must go through several interviews before getting a high-paying job. And when it comes to senior software engineers, the interview questions are often tricky. You will come across conceptual and job-based questions through your manager round interview questions for senior software engineers. Here, we have mentioned a few senior software engineer questions that are the favorite of almost all recruiters.

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Beginner

The basic sorting method known as a bubble sort involves periodically switching nearby entries in an array. Because of its high average and worst-case temporal complexity, this is not appropriate for processing large amounts of data. Bubble sort tries to solve this by first comparing adjacent elements. If the element being compared is smaller than a given threshold value, the larger one is swapped with it and vice versa if the element being compared is larger than that threshold value. Thus samples are evaluated using less space than they used to be before the swap process started, hence making this algorithm faster than its variants such as heap sort or quick sort. 

Implementation of bubble sort 

Our example uses an unsorted array. Because bubble sort requires O(n2) time, we're making it concise and direct. 

bubble sort algorithm

The first two items in a bubble sort are compared to see which one is bigger in the beginning. 

bubble sort algorithm

Value 33 is bigger than 14, therefore, which is already in sorted places in this instance. 

bubble sort algorithm

We now compare 33 with 27. Since 27 is less than 33, these two numbers must be switched. 

bubble sort algorithm

The resulting array should seem as follows: 

bubble sort algorithm

Let's next evaluate 33 and 35. These are already in ordered places, as we discover. 

bubble sort algorithm

Afterward, we get to the further two values: 35 and 10. 

bubble sort algorithm

However, we knew that 10 is less than 35. So they really aren't sorted as a result. 

bubble sort algorithm

The values are switched. We discover that the array's end has been approached. The array shall seem as follows after the first iterative process: 

bubble sort algorithm

We are specifically demonstrating the state of an array following each loop right now. After the second revision, it ought to resemble this: 

bubble sort algorithm

Remember that at least a single value shifts at the end of every iteration. 

bubble sort algorithm

Additionally, bubble sorts discover that an array is fully sorted when no switch is necessary. shown here 

bubble sort algorithm

Program : 

import java.util.Arrays; 
public class BubbleSort 
{ 
public static void main(String args[])
{
bubbleSort(new int[] { 20, 12, 45, 19, 91, 55 });
bubbleSort(new int[] { -1, 0, 1 });
bubbleSort(new int[] { -3, -9, -2, -1 });
} 
public static void bubbleSort(int[] numbers) 
 {
System.out.printf("Unsorted array in Java :%s %n", Arrays.toString(numbers));
for (int i = 0; i < numbers.length; i++) { 
for (int j = numbers.length -1; j > i; j--) { 
if (numbers[j] < numbers[j - 1]) { 
swap(numbers, j, j-1);
} 
} 
}
System.out.printf("Sorted Array using Bubble sort algorithm :%s %n", Arrays.toString(numbers)); 
} 
public static void swap(int[] array, int from, int to){ 
int temp = array[from]; 
array[from] = array[to];
array[to] = temp; 
} 
} 

Output:

Unsorted array in Java : [20, 12, 45, 19, 91, 55]

Sorted Array using Bubble sort algorithm : [12, 19, 20, 45, 55, 91]

Unsorted array in Java : [-1, 0, 1]

Sorted Array using Bubble sort algorithm : [-1, 0, 1]

Unsorted array in Java : [-3, -9, -2, -1]

Sorted Array using Bubble sort algorithm : [-9, -3, -2, -1]

A Divide and Conquer is an algorithm that splits the problem into smaller parts and solves them completely before combining the solutions. Merge Sort is a Divide and Conquer algorithm, which divides input arrays in two halves and merges these halves efficiently over a vector. 

The divide-and-conquer approach is a problem-solving paradigm that addresses problems across different areas of expertise. 

Implementation 

Let's have a look at an array with the values arr[] = 38, 27, 43, 3, 9, 82, 10 to understand how merge sort works. 

Firstly determine whether the array's left index is lower than its right index; if so, get the array's midway point. 

merge sort algorithm

However, since we already knew, until the atomic values are attained, merge sort consists of dividing arrays into equivalent parts repeatedly first. 

In this, one could see that a 7-item array is split up into two arrays with sizes of 4 and 3, accordingly. 

merge sort algorithm

Find out once more if the left index for both arrays is lower than the right index, and if so, determine the centroid for both arrays once more. 

merge sort algorithm

Furthermore, keep dividing these two arrays into smaller and smaller parts until the array's atomic units are achieved, and more subdivision becomes impossible. 

merge sort algorithm

Begin combining the items once more, relying on comparisons of element sizes following dividing the array into the smallest units. 

To integrate the elements from two lists into one, you must examine each list's elements first. 

merge sort algorithm

Following the final merger, the list appears as follows: 

merge sort algorithm

Program:

class MergeSort 

{ 
void merge(int arr[], int l, int m, int r) 
{ 
int n1 = m - l + 1; 
int n2 = r - m; 
int L[] = new int [n1]; 
int R[] = new int [n2]; 
for (int i=0; i<n1; ++i) 
L[i] = arr[l + i]; 
for (int j=0; j<n2; ++j) 
R[j] = arr[m + 1+ j]; 
int i = 0, j = 0; 
int k = l; 
while (i < n1 && j < n2) 
{ 
if (L[i] <= R[j]) 
{ 
arr[k] = L[i]; 
i++; 
} 
else 
{ 
arr[k] = R[j]; 
j++; 
} 
k++; 
} 
while (i < n1) 
{ 
arr[k] = L[i]; 
i++; 
k++; 
} 
while (j < n2) 
{ 
arr[k] = R[j]; 
j++; 
k++; 
} 
} 
void sort(int arr[], int l, int r) 
{ 
if (l < r) 
{ 
int m = (l+r)/2; 
sort(arr, l, m); 
sort(arr , m+1, r); 
merge(arr, l, m, r); 
} 
} 
static void printArray(int arr[]) 
{ 
int n = arr.length; 
for (int i=0; i<n; ++i) 
System.out.print(arr[i] + " "); 
System.out.println(); 
} 
public static void main(String args[]) 
{ 
int arr[] = {12, 11, 13, 5, 6, 7}; 
System.out.println("Given Array is :"); 
printArray(arr); 
MergeSort ob = new MergeSort(); 
ob.sort(arr, 0, arr.length-1); 
System.out.println("\nSorted array is:"); 
printArray(arr); 
} 
} 

Output:

Given array is
12 11 13 5 6 7
Sorted array is
5 6 7 11 12 13 

In the given problem, we need to count the occurrences of a given character in a string. In any programming language, this problem can have multiple solutions. Let's explain this problem a little bit further. There are numerous ways to determine the frequency of each letter, including Naive Approach, Counter Array, Java HashMap, and Java 8. 

 Here is a general working of a solution or, in more technical term, an algorithm for the problem 

  1. Set up a counter variable to keep track of the total number of times a character appears in a string. 
  2. Letter by letter, go through the entire String. 
  3. If somehow the letter in the sequence matched the designated letter, raise the value of the count parameter. 
  4. Finally, revert back to the counter variable 

For this approach, we use the StringUtils class from the Spring framework, whose static method countOccurrenceOf(String, character) accepts a Text as input and a letter and outputs the character's frequency in that Text. 

As an alternative, the Apache Commons StringUtils class for calculating the frequency of a letter in a sentence can be used to resolve this specific issue. To calculate the instances of a specific character or sub-string, use the countMatches() method of the Apache Commons StringUtils.

Program 

import org.springframework.util.StringUtils; 
public class CountCharacters { 
    public static void main(String args[]) { 
        String input = "Today is Monday"; 
        int count = StringUtils.countOccurrencesOf(input, "a"); 
        System.out.println("count of occurrence of character 'a' on String: " + " Today is Monday' using Spring StringUtils " + count); 
 int number = org.apache.commons.lang.StringUtils.countMatches(input, "a"); 
        System.out.println("count of character 'a' on String: 'Today is Monday' using commons StringUtils " + number); 
             int charCount = 0; 
        for(int i =0 ; i<input.length(); i++){ 
            if(input.charAt(i) == 'a'){ 
                charCount++; 
            } 
        } 
        System.out.println("count of character 'a' on String: 'Today is Monday' using for loop  " + charCount);  
        charCount = 0; //resetting character count 
        for(char ch: input.toCharArray()){ 
            if(ch == 'a'){ 
                charCount++; 
            } 
        }     
        System.out.println("count of character 'a' on String: 'Today is Monday' using for each loop  " + charCount); 
    }    
}

Output 

count of occurrence of the character 'a' on String: 'Today is Monday' using Spring StringUtils 2
count of character 'a' on String: 'Today is Monday' using commons StringUtils 2
count of character 'a' on String: 'Today is Monday' using for loop 2
count of character 'a' on String: 'Today is Monday' using for each loop 2

Locating the very first non-repeated letter in a Sequence of String is a frequent programming exam question. But since the concept of strings is frequently covered in coding jobs, it is best to practice with very well topics like flipping strings with recursion or determining whether a string is a palindrome. 

Dealing with all the non-repeated characters such as w, x, and y is a common problem in computational linguistics. Making a chart to hold the total of every character and selecting the very first entry that is unique will solve these issues. 

Working 

 The solution above is implemented in the getFirstNonRepeatedChar(String str) method: The character array is looped through, and each element is compared to the index of the first non-repeated character. If there is a match, then that character's count will be stored in a hash table with its corresponding position as the key and that index as the value. 

Since LinkedHashMap retains insertion order, next iterates through all the character arrays from start to finish in the following sequence to identify an item with value 1, which is your initial non-repeated character. First, it iterates through the remaining elements. Then it checks if the current character equals the value. If yes, then it concatenates the current character and repeated char. If not, then it returns a null value. 

Program 

import java.io.IOException;  
import java.util.ArrayList;  
import java.util.HashMap;  
import java.util.HashSet;  
import java.util.LinkedHashMap;  
import java.util.List;  
import java.util.Map;  
import java.util.Map.Entry;  
import java.util.Set; 
public class Programming { 
public static char getFirstNonRepeatedChar(String str) {  
Map<Character,Integer> counts = new LinkedHashMap<>(str.length()); 
for (char c : str.toCharArray()) {  
counts.put(c, counts.containsKey(c) ? counts.get(c) + 1 : 1);  
} 
for (Entry<Character,Integer> entry : counts.entrySet()) {  
if (entry.getValue() == 1) {  
return entry.getKey(); 
} 
} 
throw new RuntimeException("didn't find any non repeated Character"); 
} 
public static char firstNonRepeatingChar(String word) {  
Set<Character> repeating = new HashSet<>(); 
List<Character> nonRepeating = new ArrayList<>();  
for (int i = 0; i < word.length(); i++) { 
     char letter = word.charAt(i); 
            if (repeating.contains(letter)) { 
    continue; 
} 
if (nonRepeating.contains(letter)) {  
nonRepeating.remove((Character) letter);  
repeating.add(letter); 
 } else {  
    nonRepeating.add(letter);  
 
 
return nonRepeating.get(0);  
} 
public static char firstNonRepeatedCharacter(String word) {  
HashMap<Character,Integer> scoreboard = new HashMap<>(); 
for (int i = 0; i < word.length(); i++) {  
      char c = word.charAt(i);  
      if (scoreboard.containsKey(c)) {  
                    scoreboard.put(c, scoreboard.get(c) + 1);  
                } else { 
         scoreboard.put(c, 1);  
               }  
       } 
for (int i = 0; i < word.length(); i++) { 
            char c = word.charAt(i); 
            if (scoreboard.get(c) == 1) { 
                return c; 
            } 
        } 
        throw new RuntimeException("Undefined behavior"); 
    } 
} 

Output:

Enter the string: ssss 

didn't find any non-repeated Character 

Enter the string: missing 

First non-repeating character is m 

One of the fundamental Java duties is turning strings to integers and integers to strings, and most individuals learned about this while studying the Programming language. Provided that String and Integer are the most commonly applied types in all kinds of applications and you frequently get data between either of these types, even though String to Integer as well as Integer to String conversion is simple things at the same time, it was most helpful because of its regular necessity. 

There are various methods for converting an int value to a string. If the last example of string conversion didn't suit you, here is one given below. 

For this instance of turning an integer into a string, we utilized the static utility method String.valueOf(), which allows us to turn any integer variable into a string. 

Since the String.valueOf() function is extended to handle practically every primitive type, you may utilize it to transform any other data type—including char, double, and float—into a String. Java uses static binding to invoke the appropriate method. Here is an example utilizing String.valueOf to convert an int to a string () 

Price as a string = Price.valueOf(123); 

When the above line is executed, the integer 123 will be changed to the string "123". 

Program 

class GFG {
static int myAtoi(String str)
{
if (str == "" || str.matches("[a-zA-Z]+") || str.matches(".*[0-9].*")) {
return 0;
}
int res = 0;
for (int i = 0; i < str.length(); ++i)
res = res * 10 + str.charAt(i) - '0';
return res;
}
public static void main(String[] args)
{
String str = "8f9789";
// Function call
int val = myAtoi(str);
System.out.println(val);
}
}

Output:  

String = 1234
Integer value = 1234

String = 123s
Invalid String
Integer value = 0

A bucket sort is used to sort data into several different buckets quickly. By splitting the data into smaller groups and sorting it separately, we can avoid comparing each item individually, leaving us with a longer time for other calculations. 

Although this approach isn't language-dependent, we'll be doing the sorting in Java. So first, let's construct the working solution to arrange a collection of integers by going over the list above step-by-step. 

Algorithm for bucket sort 

bucketSort() 

Make N buckets, each holding a value range for every bin. 

Set all of the buckets' initial values to zero. 

Put components into buckets.

That corresponds to the scope for each bucket. 

Sort the items in each bucket and then

collect the items from each bucket. 

End bucketSort 

Working of Bucket sort 

Let’s take an input array 

Working of Bucket sort

Construct a 10-dimensional array. This array's slots serve as buckets for holding the items. 

Working of Bucket sort

Add items from the array into the buckets. Depending on the bucket's length, the elements are included. 

Working of Bucket sort

Every bucket's contents are sorted using one of the proven sorting algorithms. Here, quicksort was employed (inbuilt function). 

Working of Bucket sort

Every bucket's contents are collected. It is accomplished by repeatedly looping through the bucket and adding a single component to the initial array throughout every iteration. As soon as the item from the bucket is duplicated into the original array, it is removed. 

Working of Bucket sort

Program

import java.util.*;
import java.util.Collections;
class GFG {
static void bucketSort(float arr[], int n)
{
if (n <= 0)
return;
Vector<Float>[] buckets = new Vector[n];
for (int i = 0; i < n; i++) {
buckets[i] = new Vector<Float>();
}
for (int i = 0; i < n; i++) {
float idx = arr[i] * n;
buckets[(int)idx].add(arr[i]);
}
for (int i = 0; i < n; i++) {
Collections.sort(buckets[i]);
}
int index = 0;
for (int i = 0; i < n; i++) {
for (int j = 0; j < buckets[i].size(); j++) {
arr[index++] = buckets[i].get(j);
}
}
}
public static void main(String args[])
{
float arr[] = { (float)0.897, (float)0.565,
(float)0.656, (float)0.1234,
(float)0.665, (float)0.3434 };
int n = arr.length;
bucketSort(arr, n);
System.out.println("Sorted array is ");
for (float el : arr) {
System.out.print(el + " ");
}
}
}

Output:  

Bucket sort in Java
integer array before sorting
[80, 50, 30, 10, 90, 60, 0, 70, 40, 20, 50]
integer array after sorting using bucket sort algorithm
[0, 10, 20, 30, 40, 50, 50, 60, 70, 80, 90]

A counting sort is a fast sorting algorithm that sorts an array of objects based on their occurrences in the original array. For example, it can be used to find how many times any element has been compared; hence, arrangements are made such that these elements are in consecutive order. 

The counting sort swaps two elements in the array, and the key difference of this algorithm is that it returns the element counts exactly. The counting sort can work well in cases where arrays have repeated elements, and there is no need to check the array size. If a sorted version of the auxiliary array is available, then it can be used for counting rather than using the auxiliary array directly. 

Working of Counting sort 

Identify the highest element and give it the label max for the given array 

counting sort algorithm

Create a max+1-element array with every one of its items set to 0. The count of the array's items is stored inside this array. 

counting sort algorithm

Place the count of every element in the count array where it belongs. 

counting sort algorithm

Save the count array's item's calculated sum. It aids in putting the components in the appropriate position within the sorted array. 

counting sort algorithm

Identify the position of each initial array element in the count array. This displays the total number. Put the item at the determined position displayed in the following figure. 

counting sort algorithm

Program 

class CountingSort {
void sort(char arr[])
{
int n = arr.length;
char output[] = new char[n];
// Create a count array to store count of individual
// characters and initialize count array as 0
int count[] = new int[256];
for (int i = 0; i < 256; ++i)
count[i] = 0;
for (int i = 0; i < n; ++i)
++count[arr[i]];
for (int i = 1; i <= 255; ++i)
count[i] += count[i - 1];
for (int i = n - 1; i >= 0; i--) {
output[count[arr[i]] - 1] = arr[i];
--count[arr[i]];
}
for (int i = 0; i < n; ++i)
arr[i] = output[i];
}
public static void main(String args[])
{
CountingSort ob = new CountingSort();
char arr[] = { 'g', 'e', 'e', 'k', 's', 'f', 'o',
'r', 'g', 'e', 'e', 'k', 's' };
ob.sort(arr);
System.out.print("Sorted character array is ");
for (int i = 0; i < arr.length; ++i)
System.out.print(arr[i]);
}
}

Output Counting sort in Java integer array before sorting

 [60, 40, 30, 20, 10, 40, 30, 60, 60, 20, 40, 30, 40]  

integer array after sorting using counting sort algorithm

 [10, 20, 20, 30, 30, 30, 40, 40, 40, 40, 60, 60, 60]

Since arrays are fixed, and of static length, the main problem in the question isn't about finding duplicates; the main thing about this is removing the duplicates element from an array. Since we can't change or modify the array data structure, it simply means that to delete the repetitive element in array, we also need to create a new array and copy the remaining elements into that array 

While programming for any problem as a programmer, we always think about utilizing available CPU and memory. If by any chance, the input data has a lot of duplicates, there is a possibility that the requirement of CPU and memory will exceed than available, which is considered a drawback for the program. 

Since the problem doesn’t specify to use any method, just stick to any possible solution which is quick and gets the job done. Therefore, we must first turn the array into an ArrayList before using that ArrayList to generate a LinkedHashSet. 

The solution given may not be the best, but it gets the job done. It is quite possible, to some extent, to have multiple solutions, and each of them has the best or at least seems to be the best. 

Program 

import java.util.Arrays; 
import org.slf4j.Logger; 
import org.slf4j.LoggerFactory; 
public class TechnicalInterview { 
private static final Logger logger = LoggerFactory.getLogger(TechnicalInterview.class); 
public static void main(String args[]) { 
int[][] test = new int[][]{ 
{1, 1, 2, 2, 3, 4, 5}, 
{1, 1, 1, 1, 1, 1, 1}, 
{1, 2, 3, 4, 5, 6, 7}, 
{1, 2, 1, 1, 1, 1, 1},}; 
for (int[] input : test) { 
System.out.println("Array with Duplicates : " + Arrays.toString(input)); 
System.out.println("After removing duplicates : " + Arrays.toString(removeDuplicates(input))); 
} 
} 
public static int[] removeDuplicates(int[] numbersWithDuplicates) { 
Arrays.sort(numbersWithDuplicates);
int[] result = new int[numbersWithDuplicates.length]; 
int previous = numbersWithDuplicates[0]; 
result[0] = previous; 
for (int i = 1; i < numbersWithDuplicates.length; i++) { 
int ch = numbersWithDuplicates[i]; 
if (previous != ch) { 
result[i] = ch; 
} 
previous = ch; 
} 
return result; 
} 
} 

Output : 

Array with Duplicates : [1, 1, 2, 2, 3, 4, 5

After removing duplicates : [1, 0, 2, 0, 3, 4, 5

Array with Duplicates : [1, 1, 1, 1, 1, 1, 1

After removing duplicates : [1, 0, 0, 0, 0, 0, 0

Array with Duplicates : [1, 2, 3, 4, 5, 6, 7

After removing duplicates : [1, 2, 3, 4, 5, 6, 7

Array with Duplicates : [1, 2, 1, 1, 1, 1, 1

After removing duplicates : [1, 0, 0, 0, 0, 0, 2

This is one of the frequent questions this is this one, particularly during the interview. It is unique that with coding, we can solve the problem without actually reversing it. In that case, all we need to do is use a loop, but instead of going forward, we use it to look to display elements in an array from backward. So it is actually the best alternate solution possible. 

In the given below program, we didn't use this solution but instead used some libraries like import java.util.Array and, import org.apache.commons.lang.ArrayUtils.For Java, they are utilized for primitive and object arrays. The latter makes it possible to quickly inverse multiple Java array types, such as int, double, float, log, or object arrays.

The code below uses two arrays: iArray, an int array, and sArray, a collection of String objects. We have also included commons-lang-2.6.jar to use org.apache.commons.lang.ArrayUtils class to reverse Array in Java. 

The solution given here uses two arrays, iArray, an int array, and sArray, a collection of String objects, which have now been defined. To use org.apache.commons.lang, we have indeed added commons-lang-2.6.jar. Java class ArrayUtils for array reversal. Currently, we only use arrays.toString(), which is used to present the array's data. 

Program 

import java.util.Arrays; 
import org.apache.commons.lang.ArrayUtils; 
public class ReverseArrayExample { 
public static void main(String args[]) { 
int[] iArray = new int[] {101,102,103,104,105}; 
String[] sArray = new String[] {"one", "two", "three", "four", "five"}; 
System.out.println("Original int array : " + Arrays.toString(iArray)); 
ArrayUtils.reverse(iArray); 
System.out.println("reversed int array : " + Arrays.toString(iArray)); 
System.out.println("Original String array : " + Arrays.toString(sArray)); 
ArrayUtils.reverse(sArray); 
System.out.println("reversed String array in Java : "
+ Arrays.toString(sArray));
}
} 

Output:

Original int array : 

[101, 102, 103, 104, 105]

reversed int array :

[105, 104, 103, 102, 101]

Original String array :

[one, two, three, four, five]

reversed String array in Java :

[five, four, three, two, one] 

The problem and explanation to this problem is very similar to the solution explained above in question number eight. The change will only be visible in the code with a doubt. Since this question specifically told a programmer to code a program. Similar to the above solution, the case is also the same, i.e., the main thing about this is removing the duplicates element from an array. Since we can't change or modify the array data structure, it simply means that to delete the repetitive element in array, we also need to create a new array and copy the remaining elements into that array 

While programming for any problem as a programmer, we always think about utilizing available CPU and memory, so if by any chance the input data has a lot of duplicates, so there is a possibility that the requirement of CPU and memory will exceed than available which is considered as a drawback for the program. 

This time, unlike the previous solution here, we shouldn't use the org.slf5j.logger or org.slf4j.loggerfactory since this problem is specifically told to use any library. Even though we need to use the obvious library to get the solution to work, and that is Java.util. 

Program 

import java.util.*; 
public class RemoveDuplicatesFromArrayList { 
public static void main(String[] args) { 
List<Integer> numbers = Arrays.asList(1,2,2,2,3,5); 
System.out.println(numbers); 
Set<Integer> hashSet = new LinkedHashSet(numbers); 
ArrayList<Integer> removedDuplicates = new ArrayList(hashSet); 
System.out.println(removedDuplicates); 
} 
} 

Output : 

Array with Duplicates : [1, 1, 2, 2, 3, 4, 5

After removing duplicates : [1, 0, 2, 0, 3, 4, 5

Array with Duplicates : [1, 1, 1, 1, 1, 1, 1

After removing duplicates : [1, 0, 0, 0, 0, 0, 0

Array with Duplicates : [1, 2, 3, 4, 5, 6, 7

After removing duplicates : [1, 2, 3, 4, 5, 6, 7

Array with Duplicates : [1, 2, 1, 1, 1, 1, 1

After removing duplicates : [1, 0, 0, 0, 0, 0, 2

The radix sorting algorithm is much similar to the bucket sort or counting sort. However, it is an integer-based algorithm. What it means is that the values of the input array are presumed to be integers. In theory, radix sorting is considered among the quickest sorting algorithms available for the time and space requirements. 

In addition to the Counting and Bucket sort, it contains one of the few O(n) or linear time sorting algorithms. Since radix sort produces a container for every cypher (i.e., digit), it differs from bucket sort in that every container in radix sort needs to be a growable list that can accept various keys. 

For instance, since the decimal method allows ten numbers or cyphers, there are ten buckets holding decimal values (i.e., 0,1,2,3,4,5,6,7,8,9). An uninterrupted substantial digits sorting is then applied to the keys. 

In the best, medium, and worst-case scenarios, the time complexity of radix sort is O(k*n), where k is the length of the biggest number while n seems to be the size of the input array. 

We always keep in mind a n*log(n) approach would be far more appropriate if k is higher than log(n). Radix can be changed to maintain k smaller than log (n). 

Program 

import java.util.ArrayList; 
import java.util.Arrays; 
import java.util.List; 
public class Main { 
public static void main(String[] args) { 
System.out.println("Radix sort in Java"); 
int[] input = { 181, 51, 11, 33, 11, 39, 60, 2, 27, 24, 12 }; 
System.out.println("An Integer array before sorting"); 
System.out.println(Arrays.toString(input)); 
radixSort(input); 
System.out.println("Sorting an int array using radix sort algorithm"); 
System.out.println(Arrays.toString(input)); 
} 
public static void radixSort(int[] input) { 
final int RADIX = 10; 
// declare and initialize bucket[] 
List<Integer>[] bucket = new ArrayList[RADIX]; 
for (int i = 0; i < bucket.length; i++) { 
bucket[i] = new ArrayList<Integer>(); 
} 
boolean maxLength = false; 
int tmp = -1, placement = 1; 
while (!maxLength) { 
maxLength = true; 
for (Integer i : input) { 
tmp = i / placement; 
bucket[tmp % RADIX].add(i); 
if (maxLength && tmp > 0) { 
maxLength = false; 
} 
} 
int a = 0; 
for (int b = 0; b < RADIX; b++) { 
for (Integer i : bucket[b]) { 
input[a++] = i; 
} 
bucket[b].clear(); 
} 
placement *= RADIX; 
} 
} 
} 

Output

Radix sort in Java

An Integer array before sorting [181, 51, 11, 33, 11, 39, 60, 2, 27, 24, 12]

Sorting an int array using radix sort algorithm [2, 11, 11, 12, 24, 27, 33, 39, 51, 60, 181] 

The square root is the square's exact opposite. A number's square root, n, is the number that results in n whenever multiplied on its own. The square root of an integer is represented mathematically as: 

Square root of n = √ n 

In Java, numerous approaches exist to determine a given number's square root. Let's look at some of them. 

Method 1: Java programme to calculate a number's square root using the Java.lang language. Math.sqrt() formula 

import java.lang.Math; 
public class Example { 
public static void main(String[] args) { 
// declaring and initializing some double values 
double x = 25; 
double y = 81; 
// computing the square roots 
System.out.println("The square root of "+ x + " is "+ Math.sqrt(x)); 
System.out.println("The square root of "+ y + " is "+ Math.sqrt(y));
} 
} 

Output:

The square root of 25.0 is 5.0 
The square root of 81.0 is 9.0 

Method 2: Use the Java.lang.Math.pow() function to find the square root of a number using a Java programme 

To determine the square root of an integer, we can use the formula √number = number½

The program's code for this will be as follows: 

package MyPackage; 
import java.util.Scanner; 
public class SquareRoot1 { 
public static void main(String[] args) 
{ 
Double num; 
Scanner sc= new Scanner(System.in); 
System.out.print("Enter a number: "); 
num = sc.nextDouble(); 
Double squareroot = Math.pow(num, 0.5); 
System.out.println("The Square of a Given Number " + num + " = " + squareroot); 
} 
} 

Output for this program will be:

Enter a number: 81 

The Square of a Given Number 81.0 = 9.0 

Method 3: Java Program to Find the square root of a Number without using any in-built method 

The first sqrt number should be the input number / 2. Here’s a Java Program implementing the above logic. 

package MyPackage; 
public class SquareRoot 
{ 
public static double square(double number){ 
double t; 
double squareroot = number / 2; 
do
{ 
t = squareroot; 
squareroot = (t + (number / t)) / 2; 
} 
 while ((t - squareroot) != 0); 
return squareroot; 
} 
public static void main(String[] args) 
{ 
double number = 16; 
double root; 
root = square(number); 
System.out.println(" Enter a number : "+number); 
System.out.println("Square Root is: "+root); 
} 
} 

Output:

Enter a number: 22
Square Root is: 484.0 

Algorithm for Printing Pascal's triangle: 

  • Assume there are n rows in total that need to be printed. 
  • To print the rows, perform an outer iteration of i from 0 to n times. 
  • j should be iterated internally from 0 to (N – 1). 
  • Print " " in a single blank space. 
  • For left spacing, close the inner loop (j loop). 
  • For j, iterate inside the range of 0 to i. 
  • Print out I and j's nCr. 
  • Inner loop closed. 
  • After each inner iteration, print the newline character (n). 

Implementation of such an approach will be as follow: 

import java.io.*; 
class GFG { 
public int factorial(int i) 
{ 
if (i == 0) 
return 1; 
return i * factorial(i - 1); 
} 
public static void main(String[] args) 
{ 
int n = 4, i, j; 
GFG g = new GFG(); 
for (i = 0; i <= n; i++) { 
for (j = 0; j <= n - i; j++) { 
// for left spacing 
System.out.print(" "); 
} 
for (j = 0; j <= i; j++) { 
// nCr formula 
System.out.print( 
" " 
+ g.factorial(i) 
/ (g.factorial(i - j) 
* g.factorial(j))); 
} 
// for newline 
System.out.println(); 
} 
} 
} 

Output for such program will be: 

1 1 

1 2 1 

1 3 3 1 

1 4 6 4 1 

Right-angled triangles, which are created using natural numbers, are mainly called Floyd's triangle. Beginning with 1, it sequentially chooses the next larger number. Floyd's triangle bears Robert Floyd's name. 

The program's algorithm will be: 

  • Consider the amount of printed rows, n. 
  • To print rows, perform outer iteration I for n times. 
  • Internal iterations from J to I 
  • Print K and increase K 
  • After each inner repetition, print the NEWLINE character 

Let's better understand this with the help of an example: 

import java.util.Scanner; 
public class Floyd's Triangle { 
public static void main(String args[]){ 
int n,i,j,k = 1; 
System.out.println("Enter the number of lines you need in the FloyidsTriangle"); 
Scanner sc = new Scanner(System.in); 
n = sc.nextInt(); 
for(i = 1; i <= n; i++) { 
for(j=1;j <= i; j++){ 
System.out.print(" "+k++); 
} 
System.out.println(); 
} 
} 
} 

Output:  

Enter the number of lines you need in the FloyidsTriangle 

2 3 

4 5 6 

7 8 9 10 

11 12 13 14 15 

16 17 18 19 20 21 

22 23 24 25 26 27 28 

29 30 31 32 33 34 35 36 

37 38 39 40 41 42 43 44 45 

A number is said to be prime if it is only divisible by two numbers i.e. one and itself. So if any number is divisible by another number, that can't be a prime number. Multiple programs do so if you want to check whether a given number is prime or not in the Java language. Some of them are the following: 

  • Using for loop- 
public class Main { 
public static void main(String[] args) { 
int num = 29; 
boolean flag = false; 
for (int i = 2; i <= num / 2; ++i) { 
// condition for nonprime number 
if (num % i == 0) { 
flag = true; 
break; 
} 
} 
if (!flag) 
System.out.println(num + " is a prime number."); 
else 
System.out.println(num + " is not a prime number."); 
} 

Output for this program will be:

29 is a prime number. 

  • Using while loop:  
public class Main { 
public static void main(String[] args) { 
int num = 33, i = 2; 
boolean flag = false; 
while (i <= num / 2) { 
// condition for nonprime number 
if (num % i == 0) { 
flag = true; 
break; 
} 
++i; 
} 
if (!flag) 
System.out.println(num + " is a prime number."); 
else 
System.out.println(num + " is not a prime number."); 
} 
} 

Output for this program will be: 

33 is not a prime number. 

In a team, every person plays a vital role in achieving the goal. Similarly, a senior software engineer also plays a pivotal role and must have some leadership qualities. No one more than himself understands that to achieve success every day, you must work with a team. It is quite possible that you may earn success or achieve a goal for a single day or some consecutive days. Recruiters mainly ask this question about his perspective, most possibly as a leader—his way of leadership. Being a senior, he also must have a good amount of experience and also work in a team and also work as a team. So, basically, he has all the information or things that a person wants from his leader and vice versa. 

To answer this question, simply explain the leadership skills a senior leader must have. And also, some incidents as a team member and as a leader, like what difficulties a team member may face and how a leader should handle each team member for their problem. It is only essential here that recruiters aren't really interested in the bookish things that people know and talk about. They really want to listen to how you actually handle situations. Also, here is a sample answer given below. 

"I have worked as a software engineer in an ABC firm for two years. It is my first day, and I'm very nervous. The team comprises about seven people who are way more experienced than I am. However, the leader is very welcoming. He explains each of the duties as a team member and takes me to meet the team. He took the effort to go through every detail with me. I was overjoyed.

The team leader left the job some years later, and I got his position. At that time, a guy who was very intelligent without a doubt, but the only problem was he wasn't really a good team player. He pokes everyone and makes fun of everything. I started talking to him and tried to understand his problem. Later on, I realize he is a kleptomaniac, which is why he makes fun of everything and steals things over time. It wasn't exactly his fault, so I recommended him to a doctor, and he took the treatment; later on, he worked even better than me in some cases. 

Here the most vital leadership skill is patience and being a good listener. My team leader was always a good listener and without a doubt had patience, and this skill I also learned with my time working with him and also applies the same to the situation I see fit as a team leader." 

Since success in any person's life plays a vital role, any failure, either small or big, also teaches a person what most successes miss. Recruiters have almost everything you need for success like your education, skills you know or projects you have done, etc. But with this question, they want to know when exactly you fail because they know every person fails at least once in their lifetime. They want a person to accept his failure, learn from it, and most importantly, should never repeat it in the future. 

Being a senior software engineer, there are great chances that a person has work experience of at least three years and has seen the organization's ups and downs and on a personal level. Therefore, answer this question as a life lesson. Explain any incident you can think of and tell them it is a failure since right now they are interested in the failed part of your experience. While answering, briefly explain the situation and essential aspects and, most importantly, the lesson you learned from it. Here is a sample answer. 

"In my last job, our company's CEO called me in his office and assigned me a task to be a part of an interview as a senior software engineer to hire some entry-level software engineers. So I did exactly the same and hired some individuals who showed potential and had some concerns, but I clearly ignored them and thought they'd learn the things over time. For over a month, they didn't take things seriously and neglected everything their leader told them to do. They accidentally leaked some confidential data since everything got out of hand. The CEO himself fired them. At this very moment, I realized my mistakes. I took the decision in a rush. I never realized that it might bring a disaster like this. I realized I can't always have the same work; I had to be dynamic. I need to see people not just as someone who knows the work but also as their personality and willingness towards work. After this incident, I hired about five new people and also put them under my guidance so that if I ever feel there is a problem, I will be the first to handle it." 

OOP is one of the basic technical terms used worldwide, especially in the software industry. It provides a lot of essential functions, and that's what makes it most important in the industry. With this question, recruiters straightforwardly want to know what they really know about the software framework. They need the technical definition and some reasons that make it most important. Recruiters also want to know that even after the experience, they are really familiar with essential concepts like class, objects, functions, etc. They also want a candidate to share some experience, like how he used the OOP concepts in one of his code or projects. Candidates at this point also specify that they didn't share the project description since it is confidential. Also, if a person isn't hesitating while disclosing confidential information, he may not be trusted. The candidate undoubtedly explains his solo role, like how he contributed to the project but nothing else. 

To answer this question, take your time and briefly begin with a small definition of the OOP. Make your answer more practical by simply explaining the usage of OOP in the software industry, and if possible, only to ease the understanding, use some real-life examples. Make your answer brief and cover everything that may be considered essential or relevant. Give examples of the programming languages that use this concept. Almost every language uses it like c++, python, Java, etc. Explain any particular part of code where you use the OOP concept like reusability or platform independency etc. But be very direct and discreet about the information you provide to the recruiter. Here is a sample answer for reference only 

"OOP stands for Object Oriented Programming. It is basically introduced as an advantage over the previous structured programming, which is used in C language, and OOP is introduced with C++, which is basically a modified version of C language. The most important functions of OOP include reusability, inheritance, platform interdependence, and data abstraction. Apart from this, one of the key factors behind using the OOP is modularization which is basically nothing but dividing the work of software into small units called modules. These modules, once combined, work as software. I also used the OOP in almost every project. Since it is part of almost every programming language, such as Java, Python, etc., it is really hard to ignore it. I work on a module that basically needs to merge with other modules to provide all the software features but can also be used individually with some restricted features. I realize that the software can't be restricted to a single platform. It should be interdependent to the platform, so I made the whole software work since it was only a suggestion I gave my team leader really appreciates me for the thinking skill I used." 

When recruiters ask this question, it means they want to know if you can handle the pressure of multiple works assigned to you. Here, multiple tasks mean handling more than one task and continuously making some progress. It is a little tricky question. They also want to know how a candidate can maintain progress and keep a record of what needs to be done in every task assigned to them. They also expect that while dealing with such a situation, the candidate must work smartly and should use some industry standard tools that help manage his assigned tasks. 

To answer this question, start with a specific incident that matches the problem or does not include any incident. Make your answer brief as much as possible since the recruiters expect a specific answer for this situation. If you ever face the situation, then tell the same incident, and in this case, it is highly unlikely to tell them you don't face such a situation, but you will handle it this way; here explain your ways briefly. Here is a sample answer for reference 

"Yes, I've been accountable for handling multiple tasks in covid-19 time. Since the situation is worse, as you remember, companies switch to working from home. Even though the title specifically says to work from home, many people neglect their responsibilities and simply either make excuses or I can't reach them. So, being a senior software engineer, I had to include their work in my schedule. I've no other way, but the tools really do be a great help. They not only help me complete my tasks but also keep track of deadlines. To me, it was something entirely fresh. After dealing with this experience, I will no longer face any problems while handling multiple tasks later in my career. I always manage multiple tasks so easy that many people ask me how I can really do it." 

A part of the role of a software engineer also includes collecting each and every piece of information regarding the project they are working on. Similar to this on personal growth, a person must research something about the company a person is thinking of giving some time to. With this question, the recruiter wants to check what the candidate really knows about the company they are applying for. Additionally, it offers an overview of the critical skills needed for software engineers. 

To answer this simple-looking question simply, the person must research the company beforehand. Whatever the case, the candidate must either tell what they know or simply tell the recruiter that they haven't researched the company. Be sure to tell the truth about this one. With this question, the candidate may explain the company's profile and its primary operations, and if remembered correctly, do mention the CEO's name and other possible details that may help. Given below is a sample answer. If you have done brief research, then be brief about it too. Make each detail concise but cover all the necessary details. Mention details about the company's working or if the company faces any trouble over time and how it deals with it. Do mention how the company works in covid. 

"During my research on the company, I found out that there are a whole lot of clients, and some are major merchants in the field that have been served with software solutions for almost a decade. This also specifies clearly the need for efficiency, high quality, and productivity that companies demand from the employee, which is great since I've indeed worked under similar circumstances in the past. Hence, it is not really difficult for me. In addition, I learned more about the company's perks: the company also offers a one-week holiday to the best employee." 

With this specific question, all the recruiters want to know is how many things you really know. As any software engineer knows, coding is an integral part of software engineering, and most important is that they must know all the programming languages in which they can implement the same code but with more efficiency. Every programming language is made with an advantage over other programming languages. Therefore, recruiters expect an answer that not only the candidate knows multiple programming languages but also knows which programming he must choose for maximum efficiency. Knowing multiple languages is just a thing, but knowing which one to use and under what circumstances will make all the difference. 

To answer this question, simply first state how many total programming languages you know and work on. Then, if possible, mention any specific situation when you use another programming language while working on a different programming language to increase the program's overall efficiency. Make your answer brief but direct, so the recruiter knows that you do not just know the languages but are very much familiar with them. Do keep in mind that the recruiter may ask some other questions within your answer, such as what problem with the programming language you're facing so that you have to change it with another programming language and how it solves it. One of the best ways to answer this is to simply state such an incident and briefly explain the problems faced and the advantages of other programming languages that are used to remove the problem. Here is a sample answer given below. 

"As of today, knowing multiple programming languages has become a necessity. I know languages such as C, C++, Java, Python, and some scripting languages also, such as javascript. Since each language has its own advantages and disadvantages, knowing multiple languages really helped me greatly during my role as a software engineer. I used my expertise when and wherever possible since, either as a team player or a team leader must ensure that the software must not face any drawbacks while using a particular language. As a professional, I must build software without any problems and ensure overall efficiency. Over the years, my team leader really appreciated my behavior since I not only found a fault during development but also found a possible solution." 

Here the recruiter is only interested in one specific concept in the software industry: error handling. It is crucial for developing software's effectiveness. Since the software is based on logic, two or more logic may contradict each other and cause the whole software to crash or worse under particular circumstances. Recruiters specifically asked about the error handling concept to test what the candidate knows about and how he used this in practice. The recruiter doesn't really care about the theory part of the concept but is interested in knowing when and how exactly the candidate does it in a particular situation. 

To answer this question, start with the most practical definition you can think of and how this small part of the software can cause the whole software to fall apart. Keep answers short and direct since the recruiters are asking this question either they know it or have at least some knowledge about it, so saying anything won't do any good. Make the answer as detailed as possible since it is not really a tiny part. It plays a pretty pivotal role in the development of software. Also, mention there is another similar concept, exception handling, and, if possible, how they are different from each other yet still have something familiar. A short sample answer is given below. 

"Any computer system works with a basic concept of garbage in and garbage out that simply states if the input is wrong, then the output of that also won't be correct. But the human mind thinks in a totally unexpected way. But every time he gives some input, they must have a correct answer, and that is exactly where error handling comes in. Since any programmer can't really expect every possible situation in which the software must respond, all he can do is to set a possible solution to any different problem the software ever encounters. A similar concept to this is exception handling which specifically deals with the extraordinary situation that software ever encounters. One of the very basic problems is if the user wants to divide any number with zero, it becomes an exception. Here exception handling comes into play. Whereas if the user divides any number with an alphabet, that becomes an error, that is exactly where error handling is used. " 

This is one of the most loved questions that recruiters ask candidates. What they really test here is how many structures you've actually worked on and also how much you've learned so far. SDLC played a significant part in the software cycle, as it is obvious, but there are multiple SDLCs such as waterfall or spiral. Even though a candidate is familiar with the terms, working with the structure is very important. Besides this, the candidate must know where and how the models really make the difference, precisely the advantages and disadvantages.

To simply answer this question, explain the basic structure of every SDLC like planning, design, building, testing, etc. Also, be specific about the types of software development life cycle that you explain, and choose what you know the best or have worked with. Don't explain more than two or three since you have to explain other details. Be brief and accurate about the answer. Don't explain anything that you can't really specify since it will have a negative impression.

"SDLC stands for Software Development Life Cycle. It is much like a framework that produces software with the most superior quality at the minimum cost possible and in the shortest time possible. SDLC has a detailed plan for developing, planning, and maintaining software over its lifetime. 

There are many SDLC models like the prototype, waterfall, spiral, etc., but I mainly work with waterfall and prototype. The prototype model is used when the client demands it before developing software as a working prototype. It is like showing how the software looks and works after completion; if any changes are required, the client states them during the meeting. Therefore, it decreases overall time, and since the client saw the prototype so, in the end, he can't deny that what he sees is what exactly he gets. Another model I actually work with is the spiral model. Since the prototype model has a significant disadvantage that until and unless the client approves the prototype, the team didn't start working on the development of existing software, but in a spiral model, at every stage, a prototype is designed for the client so that he knows what exactly is going on and if he wants any chance he can specify and as a developer and team leader I change it with the team but most importantly here all things are continuously working." 

From this question, the recruiters want to know how much the candidate really knows about the software. Every person knows that code is an important part, but this is not exactly the complete story. As a senior software engineer, the task is not only about building software that can run on a system but also building software that performs well on all types of personal systems. Almost every person isn't really capable of owning a high-end computer system. Most people worldwide have a medium or even just a computer system that just runs the software. While developing software, a software engineer must ensure that the software's performance will remain the same on every computer system. Any client always wants software that can run on most computer systems since he thinks about the majority of people. Performance plays a significant impact not only on software but also on a computer system. If a system cannot handle the software, it may crash, and a software engineer must know and realize this fact. 

To answer this question, explain how the performance of every system is not entirely dependent upon RAM and processor but also on the program running on the system. If the program isn't optimized with the computer hardware, then it doesn't really matter how good a computer system the software takes down the whole system. Explain how and which tools can be used to manage the computer system's performance. 

"Performance really does play an important role without a doubt. And over years of working as a software engineer, I have realized this and completely understand it. Software development is not really just about making software. It also involves an important role that the software must run on any computer system, no matter the configuration. If the hardware is capable, then software must run on it and provide the expected performance. Over the years, I have specifically asked or have been told to supervise this specific thing since the client isn't the only one who will use the software. Some very specific tools are used to measure how the software performance is measured, such as tool names 1 , 2 etc. These tools are really good and give a detailed report about what is the problem or how well the software is currently performing on a particular system." 

With this question, recruiters only want to know the practical aspect of testing software. Since they know the role of testing in software development, they expect the candidate to explain the testing as a practical aspect only. Since not every software works in the same way, it is evident that the test cases made were also different and correct. Recruiters also want to know if the candidate also tests any application himself or not or does he know what it really is. With this question, the recruiter also tests a candidate for his problem-solving skills, like how he deals with it or his take on a particular problem he faced. 

To answer this question, simply explain what really software testing is, and if possible, a quick explanation about the types, but you may avoid it if the recruiter says so. Explain the role of software testing in SDLC as well as its impact in the normal world. Do share some incidents, if possible, that has a huge impact. Make everything more practical rather than theoretical. Also, if possible, do mention any incidence where you actually detect a specific problem before actually testing it really puts a positive impact. Take time but explain the answer with as much precision as possible. 

"About three or maybe four years ago, I purchased some software that I need, but due to having a medium-end system, I still cannot use the software to its full extent. I was very disappointed. And later on, when I started working in the software industry, I do keep in mind that for every software I either developed or helped, I must ensure that it ran on almost every system because till that time, I understood the urgency and the problem a person may face if the software doesn't really work in the way it is supposed to. Software testing or testing plays a pivotal role, very similar to its development of it. I also worked for some time as a software tester, so I often know that under certain circumstances, a developer only focuses more on completing the task rather than optimizing it. However, I edit them myself since I know all these prior circumstances. I discuss the problem with my manager or seniors and explain it to them along with possible solutions I see fit. They really appreciate the effort I put in and also let me fix the problem." 

Advanced

Firstly, before learning the difference between stable and unstable sorting algorithms, it's important to understand what a sorting algorithm is. In general, the sorting algorithm is the path that arranges the elements in the given list in a particular order which can lessen the complexity of the programme. 

Now let's talk about stable and unstable sorting algorithms. So, a stable algorithm must maintain the values specified in the programme in the same order of the list to distinguish them from one another. At the same time, the list values in an unstable sorting algorithm do not keep the lexical order. When sorting a collection in an unstable manner, it is not crucial that the items remain constant across sorts. 

Let's use an illustration to understand better: 

Consider sorting the key-value pairs below in decreasing order of the keys: 

INPUT: (4,2), (2,6), (1,3), (4,5), (6,1), (6,3) 

There will be two distinct solutions or outputs for the given stack, and they are: 

OUTPUT 1: (6,1), (6,3), (4,2), (4,5), (2,6), (1,3) 

OUTPUT 2: (6,3), (6,1), (4,5), (4,2), (2,6), (1,3) 

As you can see that (6,1) comes before (6,3) in the sorted order, in the same way, (4,2) comes before (4,5). So, the algorithm which will provide the 1st output is stable. 

The 2nd output is produced with an unstable sorting algorithm, as the order of objects with the same key is not maintained in the sorted order. In this output (6,3) and (4,5) are listed before (6,1) and (4,2), which is not the case in the original given input. 

DFS is the path used to find or search within the tree or any other graph structure. 

DFS for a binary tree: When there is a given binary tree structure of the program, the DFS will search all the nodes from root to leaf from the left and then jump up to the right node and will go on until it finds a solution. 

Let's understand this clearly with the help of this diagram: 

Depth First Search Algorithm

In this diagram, 0 is the root node of the binary tree, while 1 and 2 are the children of the root node. Later, their children also have children( i.e., 1 has children, 3 and 4 while 5 and 6 are children of node 2). 

But 3,4,5,6 don't have any children ahead so these are called leaves of the tree. 

 When the DFS algorithm is used for searching within the tree, it will first search from 0; then it will go on 1 and then to 3. After searching 3, it will move towards 4. Later it will jump up from 4 to 2 and then from 2 to 5. After that, it will search for 6. 

One of the well-known algorithms for sorting the values in a given list is this quicksort. When compared to other sorting algorithms, this algorithm uses the "divide and gain" strategy to sort the data input, which renders it considerably faster in practice than others (i.e it divides the large array into two different smaller arrays which makes the sorting of values very quick within the given program). Either this algorithm is interactive, or it is recursive. 

Implementation of quicksort algorithm: 

  • Submit the range (0...n) to the stack. 
  • Divide the specified array using a pivot 
  • Select the top component. 
  • Push the divisions (index range) into a stack if the range contains more than one element. 
  • Follow the procedures above until the stack is empty. 

Here's an example of the code to understand this algorithm completely:

import java.util.Arrays; 
import java.util.Stack; 
// A simple pair class in Java 
class Pair 
{ 
private final int x; 
private final int y; 
Pair(int x, int y) 
{ 
this.x = x; 
this.y = y; 
} 
public int getX() { return x; } 
public int getY() { return y; } 
} 
class Main 
{ 
public static void swap (int[] arr, int i, int j) 
{ 
int temp = arr[i]; 
arr[i] = arr[j]; 
arr[j] = temp; 
} 
public static int partition(int a[], int start, int end) 
{ 
// Pick the rightmost element as a pivot from the array 
int pivot = a[end]; 
// elements less than the pivot will go to the left of `pIndex` 
// elements more than the pivot will go to the right of `pIndex` 
// equal elements can go either way 
int pIndex = start; 
// each time we find an element less than or equal to the pivot, 
// `pIndex` is incremented, and that element would be placed 
// before the pivot. 
for (int i = start; i < end; i++) 
{ 
if (a[i] <= pivot) 
{ 
swap(a, i, pIndex); 
pIndex++; 
} 
} 
// swap `pIndex` with pivot 
swap (a, pIndex, end); 
// return `pIndex` (index of the pivot element) 
return pIndex; 
} 
// Iterative Quicksort routine 
public static void iterativeQuicksort(int[] a) 
{ 
// create a stack for storing subarray start and end index 
Stack<Pair> stack = new Stack<>(); 
// get the starting and ending index of the given array 
int start = 0; 
int end = a.length - 1; 
// push the start and end index of the array into the stack 
stack.push(new Pair(start, end)); 
// loop till stack is empty 
while (!stack.empty()) 
{ 
// remove top pair from the list and get subarray starting 
// and ending indices 
start = stack.peek().getX(); 
end = stack.peek().getY(); 
stack.pop(); 
// rearrange elements across pivot 
int pivot = partition(a, start, end); 
// push subarray indices containing elements that are 
// less than the current pivot to stack 
if (pivot - 1 > start) { 
stack.push(new Pair(start, pivot - 1)); 
} 
// push subarray indices containing elements that are 
// more than the current pivot to stack 
if (pivot + 1 < end) { 
stack.push(new Pair(pivot + 1, end)); 
} 
} 
} 
// Iterative Implementation of Quicksort 
public static void main(String[] args) 
{ 
int a[] = { 9, -3, 5, 2, 6, 8, -6, 1, 3 }; 
iterativeQuicksort(a); 
// print the sorted array 
System.out.println(Arrays.toString(a)); 
} 
} 

Output for this code will be: 

[-6, -3, 1, 2, 3, 5, 6, 8, 9] 

The insertion sort algorithm sorts the elements from the given stack by advancing the elements with a high rank toward the appropriate spot. Only one element is transferred at a time in this method. 

Putting the insertion sort method into practice:

  • Since you must order the list's elements according to its initial element, the first element in the list is always sorted. 
  • Select the element that needs to be sorted now. 
  • Check the element's value from the sub-list. 
  • Move the entries in the list that exceed the value that needs to be sorted. 
  • Add the value. 
  • The procedure is now repeated up until the list's final value is sorted. 

Let's look at an illustration to help you understand: 

Insertion sort Function:

// Insertion Sort Functionvoid insertionSort(int array[], int n)
{
int i, element, j;
for (i = 1; i < n; i++) { element = array[i]; j = i - 1; /* Move elements of arr[0..i-1], that are greater than key by one position */ while (j >= 0 && array[j] > element) {
array[j + 1] = array[j];
j = j - 1;
}
array[j + 1] = element;
}
} 

Insertion sort in C: code

#include <math.h>
#include <stdio.h>
// Insertion Sort Function 
void insertionSort(int array[], int n)
{
int i, element, j;
for (i = 1; i < n; i++) { element = array[i]; j = i - 1; while (j >= 0 && array[j] > element) {
array[j + 1] = array[j];
j = j - 1;
}
array[j + 1] = element;
}
}
// Function to print the elements of an array 
void printArray(int array[], int n)
{
int i;
for (i = 0; i < n; i++)
printf("%d ", array[i]);
printf("n");
} 

This algorithm also employs the divide and conquer approach to sort the entries in the list. Until there is just one element left in a given sub-list, it constantly divides the given list of elements into multiple sub-lists. Following that, these sublists are combined and sorted 

Implementation of merge sort algorithm:

A[p..q], starting at p. 

Until we reach the end of either L or M, pick the larger among the elements from L and M and place them in the correct position at A[p..q] 

When we run out of elements in either L or M, pick up the remaining elements and put in A[p..q] 

In code, this would look like: 

// Merge two subarrays L and M into arr 
void merge(int arr[], int p, int q, int r) { 
// Create L ← A[p..q] and M ← A[q+1..r] 
int n1 = q - p + 1; 
int n2 = r - q; 
int L[n1], M[n2]; 
for (int i = 0; i < n1; i++) 
L[i] = arr[p + i]; 
for (int j = 0; j < n2; j++) 
M[j] = arr[q + 1 + j]; 
// Maintain current index of sub-arrays and main array 
int i, j, k; 
i = 0; 
j = 0; 
k = p; 
// Until we reach either end of either L or M, pick larger among 
// elements L and M and place them in the correct position at A[p..r] 
while (i < n1 && j < n2) { 
if (L[i] <= M[j]) { 
arr[k] = L[i]; 
i++; 
} else { 
arr[k] = M[j]; 
j++; 
} 
k++; 
} 
// When we run out of elements in either L or M, 
// pick up the remaining elements and put in A[p..r] 
while (i < n1) { 
arr[k] = L[i]; 
i++; 
k++; 
} 
while (j < n2) { 
arr[k] = M[j]; 
j++; 
k++; 
} 
} 

The values of the elements in a list are compared in comparison-based algorithms to determine which element should be listed first. 

Some of the most popular and effective comparison-based sorting algorithms used to order the values in the supplied list include bubble sort, heap sort, rapid sort, merge sort, selection sort, and insertion sort. 

The best complexity these algorithms could possibly have is O(log(n!)) = O(n*log(n)), which can also be mathematically proved. Therefore, the complexity lower bound for these algorithms is nlogn

The values of the elements do not need to be compared for non-comparison-based algorithms. Instead, these methods employ unique data and internal character about the keys and functionality of the elements to sort the elements properly rather than comparing the values. The best examples of non-comparison-based algorithms include counting sort, Radix sort, and bucket sort. The essential thing to keep in mind regarding these algorithms is that the complexity lower bound is not determined because the complexity in these algorithms presumably depends on circumstances better than anything else, like 0(n). 

It is possible to sort all values using comparison-based algorithms just as easily as using non-comparison-based methods, but not the other way around. This is because algorithms that rely on comparisons require specific inputs to be used only in certain contexts. 

Sieve of Eratosthenes: This antiquated approach is used to locate every prime integer in the provided list of items up to any limit. The final number listed in the list is taken to be T. We can discover all prime integers smaller than T by applying this approach. 

The operation is performed in O(n*log(log(n))). 

Application of Eratosthenes' Sieve Algorithms for Prime Numbers: 

The Java code for this will be as follows if we need to output all prime values less than 15: 

class Solution { 
public static void printPrimes(int n) { 
if (n <= 2) return; 
boolean prime[] = new boolean[n]; 
Arrays.fill(prime, true); 
for (int i = 2; i * i < n; i++) { 
if (prime[i]) { 
for (int j = i; j * i < n; j++) { 
prime[j * i] = false; 
} 
} 
} 
int count = 0; 
for (int i = 2; i < n; i++) { 
if (prime[i]) 
System.out.print(i + " "); 
count++; 
if (count % 10 == 0) 
System.out.println(); 
} 
} 
public static void main(String args[]) { 
printPrimes(100); 
} 
} 

This code will print all the prime numbers which are less than 15, which are: 

2,3,5,7,11,13 

Binary search algorithm: It is the path to take while looking for an element in a list that has previously been sorted. The most effective algorithm to search among the elements is one that uses the divide and conquer strategy, which divides a given sorted list of items into sections and creates sub-lists until only one element is left in each sub-list. 

This approach is typically recursive since, after each iteration, whatever we perform in the list is the binary search at a smaller input. But we can accomplish it manually. 

Without using recursion, we may use the binary search technique as follows: 

import java.util.Scanner; 
/* 
 * Java Program to implement binary search without using recursion 
 */ 
public class BinarySearch { 
public static void main(String[] args) { 
Scanner commandReader = new Scanner(System.in); 
System.out.println("Welcome to Java Program to perform
binary search on int array"); 
System.out.println("Enter total number of elements : "); 
int length = commandReader.nextInt(); 
int[] input = new int[length]; 
System.out.printf("Enter %d integers %n", length); 
for (int i = 0; i < length; i++) { 
input[i] = commandReader.nextInt(); 
} 
System.out.println("Please enter number to be searched in array
(sorted order)"); 
int key = commandReader.nextInt(); 
int index = performBinarySearch(input, key); 
if (index == -1) { 
System.out.printf("Sorry, %d is not found in array %n", key); 
} else { 
System.out.printf("%d is found in array at index %d %n", key, 
index); 
} 
commandReader.close(); 
} 
/** 
* Java method to perform binary search. It accepts an integer array and a 
* number and return the index of number in the array. If a number doesn't 
* exists in array then it return -1 
* 
* @param input 
* @param number 
* @return index of given number in array or -1 if not found 
*/ 
public static int performBinarySearch(int[] input, int number) { 
int low = 0; 
int high = input.length - 1; 
while (high >= low) { 
int middle = (low + high) / 2; 
if (input[middle] == number) { 
return middle; 
} else if (input[middle] < number) { 
low = middle + 1; 
} else if (input[middle] > number) { 
high = middle - 1; 
} 
} 
return -1; 
} 
} 

Output: 

Welcome to Java Program to perform binary search on int array 

Enter total number of elements :

Enter 4 integers

10 

20 

20 

34 

Please enter number to be searched in array 

34 

34 is found in array at index 3

Welcome to Java Program to perform binary search on int array 

Enter total number of elements :

Enter 7 integers

Please enter number to be searched in array 

10 

Sorry, 10 is not found in array

This is the case because, in our estimation, a leap year is one that can be divided evenly by four. However, that is untrue. A year is only referred to as a leap year if: 

  •  It is divisible by 100 
  • If anything is divisible by 100, it should also be divisible by 400. 
  • Instead, any years that are divisible by 4 are considered leap years. 

Checking whether a given year is a leap year using an algorithm: 

  • Consider the year's integer variable. 
  • Now, give the variable a value. 
  • Now determine if the variable's value is divisible by 100; if it is, show "leap year." 
  • If the value is divisible by 100, double-check if it is also divisible by 400, and then display "leap year." 
  • If not, it will say "Not A Leap Year" on the screen 

Let's understand it better with an example: 

import java.util.Scanner; 
public class LeapYear { 
public static void main(String[] args){ 
int year; 
System.out.println("Enter an Year :: "); 
Scanner sc = new Scanner(System.in); 
year = sc.nextInt(); 
 if (((year % 4 == 0) && (year % 100!= 0)) || (year%400 == 0)) 
System.out.println("Specified year is a leap year"); 
else 
System.out.println("Specified year is not a leap year"); 
} 
} 

Binary numerals are made up only of the digits 0 and 1. Therefore, base 2 numerals can be used to express them. While decimals are integers with 10 digits, ranging from 0 to 9, The base-10 number system can be used to represent them. 

In the Java programming language, there are three alternative ways to convert a decimal number to binary: 

  1. toBinaryString() method 
  2. Custom Logic method 
  3. ParseInt() method 

Conversion of decimal into binary by Binary String() method:

We can also use the toBinaryString() method of the Integer class to convert a decimal number into binary. 

class Main { 
public static void main(String[] args) { 
// decimal number
int decimal = 91; 
// convert decimal to binary 
String binary = Integer.toBinaryString(decimal); 
System.out.println(decimal + " in decimal = " + binary + " in binary."); 
} 
} 

Conversion of decimal into binary by Custom Logic method: 

// binary number 
long num = 110110111; 
// call method by passing the binary number 
int decimal = convertBinaryToDecimal(num); 
System.out.println("Binary to Decimal"); 
System.out.println(num + " = " + decimal); 
} 
public static int convertBinaryToDecimal(long num) { 
int decimalNumber = 0, i = 0; 
long remainder; 
while (num != 0) { 
remainder = num % 10; 
num /= 10; 
decimalNumber += remainder * Math.pow(2, i); 
++i; 
} 
return decimalNumber; 
} 
} 

Conversion of decimal into binary by parseInt(): 

class Main { 
public static void main(String[] args) { 
// binary number 
String binary = "01011011"; 
// convert to decimal 
int decimal = Integer.parseInt(binary, 2); 
System.out.println(binary + " in binary = " + decimal + " in decimal."); 
} 
} 

While you reverse a number, the first integer's placement is switched to the last integer's, the second integer's position is switched with the second last digit's, and so on until it reaches the center. The two methods used to flip the integers are as follows: 

  1. Using while loop 
  2. Using recursion 

Reversing the given integer using while loop: 

public static void main(String[] args)
{
int number = 987654, reverse = 0;
while(number != 0)
{
int remainder = number % 10;
reverse = reverse * 10 + remainder;
number = number/10;
}
System.out.println("The reverse of the given number is: " + reverse);
}
}

Output for the given program will be: 456789 

Reversing the given integer using recursion: 

public static void reverse number(int number)
{
if (number < 10)
{
//prints the same number if the number is less than 10
System.out.println(number);
return;
}
else
{
System.out.print(number % 10);
reverseNumber(number/10);
}
}
public static void main(String args[])
{
System.out.print("Enter the number that you want to reverse: ");
Scanner sc = new Scanner(System.in);
int num = sc.nextInt();
System.out.print("The reverse of the given number is: ");
//method calling
reverseNumber(num);
}
}

To identify the highest repeated words in a file in Java, utilise the map and map.entry interfaces. 

Let's use an illustration to better grasp this: 

Assume that the sample text file has the following information: 

Input: A text file containing a sequence of arbitrary words

"How to count the number of occurrences of each word? How to count numbers or each word in a string. Calculating the frequency of each word in a sentence in Java." 

// Java Program to Find the 
// Most Repeated Word in a Text File 
// Importing File classes 
import java.io.File; 
import java.io.FileNotFoundException; 
// Importing Map and HashMap class from 
// java.util package 
import java.util.HashMap; 
import java.util.Map; 
import java.util.Map.Entry; 
// Importing Scanner class to 
// take input from the user 
import java.util.Scanner; 
// Class
// To find maximum occurrences 
public class GFG { 
// Method 1 - getWords() 
// Reading out words from the file and 
// mapping key-value pair corresponding to 
// each different word 
static void getWords(String fileName, 
Map<String, Integer> words) 
throws FileNotFoundException 
{ 
// Creating a Scanner class object 
Scanner file = new Scanner(new File(fileName)); 
// Condition check using hasNext() method which 
// holds true till there is word being read from the 
// file.
// As the end of the file content, condition violates 
while (file.hasNext()) { 
// Reading word using next() method 
String word = file.next(); 
// Frequency count variable 
Integer count = words.get(word); 
// If the same word is repeating 
if (count != null) { 
// Incrementing corresponding count by unity 
// every time it repeats 
// while reading from the file 
count++; 
} 
else 
// If word never occurred after occurring 
// once, set count as unity 
count = 1; 
words.put(word, count); 
} 
// Close the file and free up the resources 
file.close(); 
} 
// Method 2 - getMaxOccurrence() 
// To get maximum occurred Word 
static int getMaxOccurrence(Map<String, Integer> words) 
{ 
// Initially set maximum count as unity 
int max = 1; 
// Iterating over above Map using for-each loop 
for (Entry<String, Integer> word : 
words.entrySet()) { 
// Condition check 
// Update current max value with the value 
// exceeding unity in Map while traversing 
if (word.getValue() > max) { 
max = word.getValue(); 
} 
} 
// Return the maximum value from the Map 
return max; 
} 
// Method 3 
// Main driver method 
public static void main(String[] args) 
throws FileNotFoundException 
{ 
// Creating an object of type Map 
// Declaring object of String and Integer types 
Map<String, Integer> words 
= new HashMap<String, Integer>(); 
// Retrieving the path as parameter to Method1() 
// above to get the file to be read 
getWords("C:\\Users\\dell\\sample.txt", words); 
// Variable holding the maximum 
// repeated word count in a file 
int max = getMaxOccurrence(words); 
// Traversing using fo-each loop 
// Creating a set out of same elements 
// contained in a HashMap 
for (Entry<String, Integer> word : 
words.entrySet()) { 
// Comparing values using geValue() method 
if (word.getValue() == max) { 
// Print and display word-count pair 
System.out.println(word); 
} 
} 
} 

Output for this program will be:

in = 3 

each = 3 

of = 3 

to = 3 

The pyramid program is one of the patterns printing programs. Pattern printing programs help the developer to build the basic logic required in programming, and it also helps to get acquainted with the loops in Java.

There are three types of pattern programs in Java. 

Star Patterns in Java 

Number Patterns in Java 

Alphabet/Character Patterns in Java 

We'll discuss the star pattern program as pyramid structure is one type of star pattern program. 

Pyramid Program 

A star pattern program that looks like a pyramid, is called Pyramid program in Java. In this program, we set the initial value of st as 1 and sp as n - 1. How did we come to these values?

We came to these values by observing the pyramid pattern. 

import java.util.*; 
public class Main { 
public static void main(String[] args) { 
Scanner scn = new Scanner(System.in); 
int n = scn.nextInt(); 
int st = 1; // number of stars 
int sp = n - 1; // number of spaces 
// 1st for loop for rows 
for(int i = 0; i < n ; i++){
// 2nd for loop for printing spaces 
for(int j = 1; j <= sp; j++){
System.out.print("\t"); 
} 
// 3rd for loop for printing stars 
for(int j = 1; j <= st; j++){
System.out.print("*\t"); 
} 
st+=2; 
sp--; 
System.out.println(); 
} 
} 
} 

Output for this program will be as shown in picture: 

Pyramid structure

Various methods determine whether the given number is even or odd. The following are some of the most effective methods or operators for checking this: 

1. Using the bitwise operator (&). The following program will check the number: 

import java.util.*; 
public class Main { 
static int isEven(int n) 
{ 
return (n & 1); 
} 
public static void main (String[] args) 
{ 
Scanner sc = new Scanner(System.in); 
int n; 
System.out.println(“Enter the number :”); 
n = sc.nextInt(); 
if(isEven(n) == 0) 
System.out.print(“Even\n”); 
else 
System.out.print(“Odd\n”); 
} 
} 

2. By dividing and multiplying the figure by 2. The amount should be multiplied by 2 and divided by 2. It is an even number if the outcome matches the input; otherwise, it is an odd number. This program's algorithm will be: 

import java.util.*; 
public class Main { 
static boolean isEven(int n) 
{ 
return ((n / 2) * 2 == n); 
} 
public static void main (String[] args) 
{ 
Scanner sc = new Scanner(System.in); 
int n; 
System.out.println(“Enter the number :”); 
n = sc.nextInt(); 
if(isEven(n)) 
System.out.print(“Even\n”); 
else 
System.out.print(“Odd\n”); 
} 
} 

3. By repeatedly switching a temporary variable n times with a true initial value. N is even if the flag variable is given back its initial value, which is true. N is false if not. The following is the algorithm for this method: 

import java.util.*; 
public class Main { 
static boolean isEven(int n) 
{ 
boolean even_no = true; 
for (int i=1; i <= n; i++) 
even_no = !even_no; 
return even_no; 
} 
public static void main (String[] args) 
{ 
Scanner sc = new Scanner(System.in); 
int n; 
System.out.println(“Enter the number :”); 
n = sc.nextInt(); 
if(isEven(n)) 
System.out.print(“Even\n”); 
else 
System.out.print(“Odd\n”); 
} 
} 

To add two numbers without using the plus operator, two numbers will be entered. Then, according to the algorithm, an operation will be performed that returns the sum of those two numbers. Let's use an illustration to grasp this better: 

Let's say we provide the inputs 35 and 20. Then, without utilizing an addition operator, our application will output 55. 

The program for this will be: 

import java.util.Scanner; 
public class Main { 
public static void main(String[] arg)
 { 
int x, y ; 
Scanner sc = new Scanner(System.in);
System.out.print("Please Give first number: "); 
x = sc.nextInt();
System.out.print("Please Give second number: "); 
y = sc.nextInt();
while(y != 0){ 
int temp = x & y; 
x = x ^ y; 
y = temp << 1; 
} 
System.out.print("Sum = "+x);
System.out.print("\n");
}
}

With this question, all the recruiters want an answer as to how a person, either as a team leader or team member, will maintain the quality of the software as a whole since everyone knows that not a single person really can't develop an entire software while maintaining everything in software such as performance, optimization, quality, etc. Therefore, recruiters want a candidate to discuss the role of quality from a candidate's perspective. They are not even a single person interested in how theoretically you know the role of quality but precisely how a candidate maintains quality and what possible problem he may or may not face. 

Since, as discussed, the recruiter is not really interested in theoretical data so, start your answer from your own experience and explain the role of quality in software development. Explain all the things related to this as a part of a team or as a team leader. Discuss the problems you face and how you really get to maintain the quality. Since the recruiter is only interested in experience, tell him an exceptional experience where you are in whatever role, either as a team player or team leader. Finally, explain the quality control process. 

"Over the years, I have been part of multiple teams and managed teams as team leaders. As a result, I meet different people with expertise in their skill sets. Some of the people I met are not really good team players, but over time, they become one. Working in either a role as a team member or a team leader made me realize the importance of every member of a team. If by any means any team member or team leader themself was not working with their full potential, then the result of the project they work on won't be any good. It may get the job done, but the quality of the project suffers. 

During this software development process, there is a specific stage or process called the quality control process. It simply states that any business must seek to ensure the quality of the product is either improved or maintained. In this process, quality is ensured. For any project, an appropriate standard of quality since quality does play a significant role in software." 

With this problem, all the recruiters want to know is how good you are as a team player. Since any project can't be handled by an individual alone. For every project, whether it is software development or otherwise, there is a need for specialized individuals that work together, put all their efforts,, and complete the project in the best possible manner.

Since, as everyone knows, while working in a team, there is a high possibility that team players' interests may collide with each other, and handling that scenario is also an aspect that recruiters want to know about the candidates. Any team leader can't think that every team member should work according to them. Therefore, accept any work that is assigned to you. Well, as a team leader, he also faces these similar types of problems almost every day. Recruiters want to know if the candidate ever faces such a similar situation since, as a senior, he must work with the team. It is also quite possible that they may disagree with some orders, so handling this situation correctly is a vital part of this question. 

Begin the answer with an agreement to the condition that you also face such a scenario where you as a team player get into a disagreement with the team leader or other team member about how the team leader really handles this situation. You may face this exact scenario, so simply, after agreeing to the statement, just explain the scenario exactly as you experienced. You may hide some less important details, such as names of employees, etc., but make it as honest as possible since recruiters are also in this exact situation, so if you lie, they will surely realize it. 

"I completely agree with the statement that while working as a team player, I do sometimes have disagreements with other persons, and it also happens with me while I work as a team leader. Over my five years of career, I have learned much from this experience. So, I worked as a software tester about two years ago, and I really enjoy this specific role. My team leader is very happy with my approaches and solution. Still, this thing changed when my head of department switched my role as a presenter, which included tasks such as meeting with clients, presenting his idea, and other similar duties. So, since it is a new role, I wanted to try so I did. But after some time, I tend to disagree with the team almost like every now and then. Since what I told them and what I developed almost missed something, or there was some problem. I became so frustrated since I had to deal with the client complaints, but later at some point, I realized that I was also the supervisor of the development team. I explained the situation to my seniors, and they agreed that if a person who deals with a client's requests also be a supervisor, it decreases the overall time taken while developing software. Not only this, they make this position permanent, like if a person is dealing with clients, they should also be the supervisor of the team working on that project. Now clients are very happy with the service of the company." 

This question really can't be easy since it is a situational-based question that also, in a way, checks what kind of person you are. The recruiters, apart from all the technical terms and theoretical knowledge that you really know, explain this question as efficiently as possible. Also, do assume that the boy never heard about coding or programming. But since the boy is 5-year-old so, explain the answer with a possible example. This question is not about how he would explain this concept to a person but also how well he really knows this concept on a fundamental level. As we know, a lot of people are involved in software development, and not all people are from technical backgrounds. So, explaining a simple technical concept to a non-technical person makes this question most incredible and different. On the other hand, it is pretty easy to talk to a person with similar background about the difficulties they face in day-to-day operations. 

To answer this question, take some time and do not rush to answer at least this question. Since by any chance you stop or say something wrong, it shows carelessness. Instead, pick a concept that looks as beginner as possible now since the person is already 5-year-old. You explain to him some basic things about coding or programming. Do remember not to use any technical term here since the kid most possibly never heard about the term, which will make the question more complex. Give him an example that explains the importance of the following rules, then explain what an algorithm really is now. As soon as he understands it, simply explain the coding part. 

"As we know from birth, we do not have all the information and similarly in computers also they do not know anything and do nothing since they don't know anything at all. When you first start school, you learn the names by naming them or viewing pictures under which the name is written. So there is a sequence here: during the class, when the first teachers enter the room, she teaches you something, then the next teacher comes, and then she also teaches you something. As you notice, there is a sequence of steps you need to take to a certain point where you are today, like right now, you know a lot more than you first started school. Like this coding is also a sequence where you do something to achieve a particular result like your result is gaining knowledge and you achieved it. Similarly, with coding, we instruct a computer system to achieve our goal. So, when we calculate two numbers on a computer, we enter the first number then choose the operation we want like addition, subtraction, etc., and now we enter the second number and hit the result, and we get it." 

Making decisions is also a critical role of a senior member in any organization. The recruiters may expect this answer to test the candidate's decision-making power. Since not everyone can make any decision or when it comes to critical decisions, many people tend to worry or think about consequences before taking any decision at all. 

To answer this question, simply explain any recent experience where you took a crucial decision, whatever the outcome, but having what to take to decide is a crucial aspect of this question. Undoubtedly, getting a positive result is also an essential role since decisions are meant to bring positive results. 

"It is an incident in my last job that I need to take a very critical decision. It was not really my call to make, but since my senior wasn't at the time, I had to make a very critical decision. What happens is that after the software development, my friend who is also my team leader, is absent for some reason. So, I found that on a certain condition, the software recently developed will crash not because of bad programming but a malicious script that someone has planted. Now the important part here is that to fix it we first had to clean all the computers, which took at least a day, and the deadline was that day. We try reaching the team leader, but he won't respond. So as the next senior member of the team, I suggest that I should be the one who explains it to the client as well as my superiors. And I did even though the client and my superiors were very upset with the situation. Still, he really appreciated the fact that I told him everything even without having the team leader present." 

This question explicitly targets what you really know about this term since it is not a popular term. Most software engineers generally talk about the worst case or best case in the scenario. Recruiters want to hear what a candidate really knows about this term and, apart from technical know-how, what the candidate knows about this. The answer can be easy or can be complex. It Is totally up to the candidate how he explains it. Whatever the case the candidate speaks, he must stick to it if cross-questioned. The recruiters also want the candidate to explain it with some possible explanations. 

To answer this question, simply start with a basic definition of the term and then explains it briefly. Then, since it is somehow a representation of the program's complexity, explain some problems or experiences you have over time working. 

"Any code or program has some complexities with it. Currently, no program can achieve only the best case since every program has some limitations. Big O notation is nothing but the representation of how efficient a program's algorithm is. It is measured on two basis, space and time complexities. It is easy to represent both in a graph, so most of the time, while calculating the big O notation, generally people use the graphs as a medium to show the progress." 

Yet another advanced-level question for a senior software developer. There are several reasons why an interviewer or recruiter puts up this question. First, being a senior software developer, you will need to showcase your experience and expertise in the field of software engineering, and that's exactly what recruiters are looking for in this particular question. A person can only answer this question without submitting if they have practiced thoroughly and actually have industry-level experience. Secondly, the recruiters also want to have some insights regarding the industry's future from the candidate so that they can judge the level of your creativity and clarity in your opinions. Here's a sample answer for you to prepare:

Example: "The software engineering sector is quickly expanding and is anticipated to expand at a higher rate shortly. In today's date, several organizations are dependent on software to manage their operations smoothly. Hence, the requirement for software developers is about to extend soon. In addition, the sector is becoming international, with more corporations outsourcing software development to nations with cheaper labor costs. This tendency is projected to continue, making the software engineering sector more competitive and hard in the future." 

You might come across a senior sdet interview questions where the recruiter asks for your opinion on the challenges that the field of software engineering might face. They ask it merely to test your knowledge of the field and your opinion on the question. Make sure you answer the question confidently to gain your recruiter's attention. But, to do so, you must know precisely what challenges might come up for engineers in the next decade.

According to a renowned futurist speaker, "every firm in the future will be a software company." This attitude has been repeated by other corporate speakers who have given similar speeches. With the expansion of the engineering industry, several issues have emerged. The difficulties are as follows: 

  • Budgetary restrictions on software quality 
  • Project deadlines are being missed. 
  • Unexpected and unplanned technological failures 

When it comes to large-scale systems, writing code isn't sufficient. It is critical to coordinate numerous other aspects alongside any software activities. The aspects include: 

  • Analyses of costs 
  • Project preparation 
  • Project administration 
  • Management of the development team 
  • Choosing the Proper Tools 
  • Reporting on Automated Testing 

The organization and you as a developer must keep these challenges in mind going forward. You can point out some of these challenges. Have a look at the answer below for better clarity.

Example: "The software engineering sector will encounter several problems during the next decade." Maintaining the ever-changing technology landscape is one of the most challenging problems. Managing software systems' rising complexity. With the rise in cyber assaults, it is critical to guarantee that software systems are secure. It gets increasingly difficult to guarantee that systems are operating correctly as they become more complicated. As new technologies arise, software developers must adapt and learn how to use them. " 

To ace this question put up by your recruiter, you need to ace up some of the advice that an experienced senior software developer will give to anyone in the field of software engineering. Like any other question an interviewer might ask, this one is precise to test your quality as a senior as you will have to. Being a senior, you not only have to write a piece of code all by yourself but guide junior engineers under you. Through this question, recruiters want to understand your skill at guiding people in the right direction.

Example: "I would recommend a few tips to anyone willing to pursue their career as a software developer. First and foremost, solid arithmetic abilities are required. Second, it's crucial to have a grasp of problem-solving abilities. Third, I recommend they approach any problem by breaking it down into simpler ones. This is because, as per my experience, complex challenges are frequently broken down into smaller, which gets more manageable components in software engineering. Third, because software engineering includes dealing with algorithms and data structures, the ability to comprehend and apply sophisticated mathematical ideas is vital. As a result, understanding the large picture and then identifying the little actions that must be made to fix the problem is critical. Finally, excellent communication skills are essential. Because software engineering is frequently a collaborative job, being able to communicate effectively is essential." 

An interviewer may ask a senior software engineer this question for various reasons. One of the most common reasons to put up such a question is testing the knowledge of engineers on the profession they are in and how acquainted they are with the difficulties. Secondly, the interviewer might want to test how sure a candidate is about himself or, in other words, the self-awareness of the engineer. Lastly, they would also like to review the engineer's capacity to consider the profession critically. 

Furthermore, by asking such a question, the interviewer will understand the senior software engineer's perspective on the profession. A recruiter needs to have an insight into how aware a candidate is about their own career. This question can also assist the interviewer in evaluating the engineer's ability to think critically about their profession and identify areas for development. 

Example: "The ever-increasing complexity of software systems is that It gets more difficult to design software systems using classic methodologies such as waterfall or spiral as they become more complicated. The most significant challenges are the need for more rigorous and formal development methodologies and improved techniques and tools. As a result, more formal methodologies, such as agile or extreme programming, are required. Furthermore, as software systems get more sophisticated, improved tools and approaches for managing their development are required." 

Because software engineering is constantly growing, it is critical to keep current on the newest breakthroughs and concerns to deliver the best products and services available. The Senior Software Engineer may better plan for the future and keep their organization at the forefront of the industry by knowing the most severe challenges confronting software engineering today. 

Example: "There are several critical concerns confronting software engineering today, but some of the most serious are as follows: 

The requirement for improved methods of dealing with old code. As software systems age, it can become more challenging to use the same codes for a longer time duration or maintain the code. Often this increases the overall expenses of the organization.

The need for more efficient methods of addressing objectives. Requirements management is an essential component of every software project; however, it sometimes gets pretty tricky to address, especially for big and complicated projects. 

The requirement for improved project management procedures. Traditional project management methodologies are usually unsuitable given the rising complexity of software projects. 

The requirement for improved tools and methods to assure software quality. The hazards associated with low-quality software grow as software grows increasingly complicated and vital to organizations and society. 

Description

A senior software developer has several roles and responsibilities apart from coding. Hence, the recruiter judges a senior software engineer an applicant on both concept base and job base questions. In addition, by asking senior software developer interview questions based on the job, they note your personality, experience, and qualifications for the position you are applying for. To ace your following interview, ensure you grasp the principal software engineer interview questions mentioned in this article. Moreover, we would recommend you enrich your answer with confidence and clarity. Finally, make sure you have mastered communication skills as well.  

These last few days' preparations will help you with your software engineer career. However, suppose you have more time on hand. In that case, you can always look into some of the best Full Stack Web Development courses. These courses will clear out your basics and advanced level concepts in the field of web development and prepare you for placements in companies offering a high salary.

There are several good courses out there, of which we would recommend Full Stack Web Development course with KnowledgeHut. Through this full stack development course, one can develop in-demand skills from the ground level. The course has several lectures recorded and in-class live training to make you job-ready.

Coming back to the interview, as long as you are good with these senior QA engineer interview questions and researched well regarding the company you are applying for, you have a high chance of landing your dream job. You can also research your interviewer to know the senior set of interview questions they can put up.  

As a senior software developer, you might have seen several interviews already, and you would know how important a last-night checklist is. The day before your interview, look at your resume, cover letter, and job description. Give attention to minute details.  

Before going for the interview, be hundred and one percent sure of a few things: 

  1. You should always carry a physical copy of your resume to the interview. 
  2. The impression does matter. Interviewees can know your personality from the way you talk, the way you walk, the way you sit, and the way you dress. Your dress code should be formal. 
  3. No matter the situation, try your best to arrive at the interview on time.  

After appearing for the interview, leave a thank you note to your interviewers. In addition, craft a customized thank you note by mentioning your learning experience in the interview. If there are multiple interviewers, have a thank you note for each of them. These tips and tricks will help you in boosting your confidence in the interview. But, of course, the rest depends on your preparation and skills.  

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