XpressBees Software Developer Interview Questions and Answers for Freshers

Round duration - 45 minutes
Round difficulty - Medium

Technical Interview round with questions on DSA.

Q1. 
Reverse Words in a String: Problem Statement
You are given a string of length N. Your task is to reverse the string word by word. The input may contain multiple spaces between words and may have leading o...read more
Ans. 
Reverse words in a string while handling leading, trailing, and multiple spaces.
• Split the input string by spaces to get individual words

• Reverse the order of the words

• Join the reversed words with a single space in between

• Handle leading, trailing, and multiple spaces appropriately
Answered by AI
Add your answer
Q2. 
Reverse a Stack Using Recursion
You are given a stack of integers. Your task is to reverse the stack using recursion without using any extra space other than the internal stack space used due to recursion...read more
Ans. 
Reverse a stack using recursion without using any extra space other than the internal stack space.
• Use recursion to pop all elements from the original stack and store them in function call stack.

• Once the stack is empty, push the elements back in reverse order.

• Base case of recursion should be when the original stack is empty.
Answered by AI
Add your answer

Round duration - 45 minutes
Round difficulty - Medium

Technical Interview round with questions on DSA.

Q1. 
Convert a Binary Tree to its Mirror Tree
Given a binary tree, convert this binary tree into its mirror tree. A binary tree is a tree in which each parent node has at most two children. The mirror of a bin...read more
Ans. 
Convert a binary tree to its mirror tree by interchanging left and right children of all non-leaf nodes.
• Traverse the binary tree in a recursive manner.

• Swap the left and right children of each non-leaf node.

• Continue this process until all nodes have been processed.
Answered by AI
Add your answer
Q2. 
Remove Nth Node from End of Linked List
You are given a singly linked list with 'N' nodes, each containing integer data, and an integer 'K'. Your goal is to remove the 'K'th node counting from the end of ...read more
Ans. 
Remove the Kth node from the end of a singly linked list.
• Use two pointers approach to find the Kth node from the end.

• Handle edge cases like removing the head node or removing the last node.

• Update the pointers to remove the Kth node and reconnect the list.
Answered by AI
Add your answer

Round duration - 30 minutes
Round difficulty - Easy

Typical Managerial round.

Round duration - 60 Minutes
Round difficulty - Medium

The interviewer asked me 2 questions related to DS/Algo in this round . Both the questions were of Easy-Medium difficulty and I was also required to code them in a production ready manner.

Q1. 
Maximum Sum Path in a Binary Tree Problem Statement
You are provided with a binary tree consisting of N nodes where each node has an integer value. The task is to determine the maximum sum achievable by a...read more
Ans. 
Find the maximum sum achievable by a simple path between any two nodes in a binary tree.
• Traverse the binary tree to find all possible paths and calculate their sums.

• Keep track of the maximum sum encountered during traversal.

• Consider paths that may include the same node twice.

• Implement a recursive function to explore all possible paths.

• Handle cases where nodes have negative values.
Answered by AI
Add your answer
Q2. 
Intersection of Two Arrays Problem Statement
Given two arrays A and B with sizes N and M respectively, both sorted in non-decreasing order, determine their intersection.
The intersection of two arrays in...read more
Ans. 
The problem involves finding the intersection of two sorted arrays efficiently.
• Use two pointers to iterate through both arrays simultaneously.

• Compare elements at the pointers and move the pointers accordingly.

• Handle cases where elements are equal, and update the intersection array.

• Return the intersection array as the result.
Answered by AI
Add your answer

Round duration - 50 Minutes
Round difficulty - Medium

This round had 2 questions of DS/Algo to solve under 50 minutes and one question related to Operating Systems.

Q1. 
Next Greater Element Problem Statement
You are provided with an array or list ARR containing N positive integers. Your task is to determine the Next Greater Element (NGE) for each element in the array.
T...read more
Ans. 
Find the Next Greater Element for each element in an array.
• Iterate through the array from right to left

• Use a stack to keep track of elements with no greater element to the right

• Pop elements from the stack until finding a greater element or stack is empty
Answered by AI
Add your answer
Q2. 
Number In Arithmetic Progression Problem
Given three integers X, C, and Y, where X is the first term of an arithmetic sequence with a common difference of C, determine if Y is part of this arithmetic sequ...read more
Ans. 
Check if a given number is part of an arithmetic sequence with a given first term and common difference.
• Calculate the arithmetic sequence using the formula: nth term = X + (n-1) * C

• Check if Y is equal to any term in the sequence to determine if it belongs to the sequence

• Return 'True' if Y belongs to the sequence, otherwise return 'False'
Answered by AI
Add your answer
Q3. Can you define process and threads in operating systems?
Ans. 
Processes are instances of programs in execution, while threads are smaller units within a process that can execute independently.
• A process is a program in execution, consisting of code, data, and resources.

• Threads are smaller units within a process that can execute independently.

• Processes have their own memory space, while threads share the same memory space within a process.

• Processes are heavyweight, while threads ar...read more
Answered by AI
Add your answer

Round duration - 50 Minutes
Round difficulty - Medium

This round had 2 questions of DSA of Easy-Medium difficulty and at the end I was asked a Puzzle to check my general problem solving ability.

Q1. 
Max Product Subset Problem Statement
Given an array/list arr of size n, determine the maximum product possible by taking any subset of the array/list arr. Return the result modulo 10^9+7 since the product ...read more
Ans. 
Find the maximum product of a subset of an array modulo 10^9+7.
• Iterate through the array and keep track of the maximum positive product and minimum negative product encountered so far.

• Handle cases where the array contains zeros separately.

• Return the maximum product modulo 10^9+7.
Answered by AI
Add your answer
Q2. 
Populating Next Right Pointers in Each Node
Given a complete binary tree with 'N' nodes, your task is to determine the 'next' node immediately to the right in level order for each node in the given tree.
...read more
Ans. 
Implement a function to update 'next' pointers in a complete binary tree.
• Iterate level by level using a queue

• Connect nodes at each level using 'next' pointers

• Handle null nodes appropriately

• Ensure the tree is a complete binary tree
Answered by AI
Add your answer
Q3. You have two wires of different lengths that are both capable of burning for exactly one hour when ignited at both ends. How can you measure a time interval of 45 minutes using these two wires?
Add your answer

Round duration - 50 Minutes
Round difficulty - Medium

This round consisted of 2 questions from DSA where I was first asked to explain my approach to the interviewer with proper complexity analysis and then code the problems. The interviewer was quite friendly and also provided me some hints when I was stuck.

Q1. 
Stack with getMin Operation
Create a stack data structure that supports not only the usual push and pop operations but also getMin(), which retrieves the minimum element, all in O(1) time complexity witho...read more
Ans. 
Implement a stack with push, pop, top, isEmpty, and getMin operations in O(1) time complexity without using extra space.
• Use two stacks - one to store the actual elements and another to store the minimum element at each level.

• When pushing an element, check if it is smaller than the current minimum and update the minimum stack accordingly.

• When popping an element, also pop from the minimum stack if the popped element is t...read more
Answered by AI
Add your answer
Q2. 
Split Array Into Maximum Subarrays Problem Statement
You are given an integer array arr of size N. Your task is to split the array into the maximum number of subarrays such that the first and last occurre...read more
Ans. 
Given an array, split it into maximum subarrays with first and last occurrence of each element in a single subarray.
• Iterate through the array and keep track of the first and last occurrence of each element.

• Use a hashmap to store the indices of each element.

• Split the array whenever the last occurrence of an element is found.
Answered by AI
Add your answer

Round duration - 60 minutes
Round difficulty - Easy

I couldn't find an optimal approach to the first question, so she skipped that question and proceeded to next questions. Remaining questions I have answered satisfactorily.

Q1. 
Subset Sum Equal To K Problem Statement
Given an array/list of positive integers and an integer K, determine if there exists a subset whose sum equals K.
Provide true if such a subset exists, otherwise r...read more
Ans. 
Given an array of positive integers and an integer K, determine if there exists a subset whose sum equals K.
• Use dynamic programming to solve this problem efficiently

• Create a 2D array to store if a subset with a particular sum exists

• Iterate through the array and update the 2D array accordingly

• Check if the value at the end of the iteration is true for the given K
Answered by AI
Add your answer
Q2. 
BFS Traversal in a Graph
Given an undirected and disconnected graph G(V, E) where V vertices are numbered from 0 to V-1, and E represents edges, your task is to output the BFS traversal starting from the ...read more
Ans. 
BFS traversal in a disconnected graph starting from vertex 0.
• Implement BFS algorithm to traverse the graph starting from vertex 0.

• Use a queue to keep track of visited nodes and their neighbors.

• Ensure to print the traversal sequence in the correct order.

• Handle disconnected components by checking for unvisited nodes.

• Follow the BFS approach of exploring neighbors before moving to the next level.
Answered by AI
Add your answer

Round duration - 60 minutes
Round difficulty - Easy

I told that my strength is problem solving and I can always find a way when there is a bottle-neck. Gave some examples of my experiences while doing my assignments.

Q1. 
Replace Spaces in a String
Given a string STR consisting of words separated by spaces, your task is to replace all spaces between words with the characters "@40".
Input:
The first line contains an integ...read more
Ans. 
Replace spaces in a string with '@40'.
• Iterate through each character in the string

• Replace spaces with '@40'

• Return the modified string
Answered by AI
Add your answer

Round duration - 60 minutes
Round difficulty - Easy

Technical Interview Round with questions based on Data structures, OOPS and SQL.

Q1. 
Delete a Node from a Linked List
You are provided with a linked list of integers. Your task is to implement a function that deletes a node located at a specified position 'POS'.
Input:
The first line co...read more
Ans. 
Implement a function to delete a node from a linked list at a specified position.
• Traverse the linked list to find the node at the specified position.

• Update the pointers of the previous and next nodes to skip the node to be deleted.

• Handle edge cases such as deleting the head or tail of the linked list.

• Ensure to free the memory of the deleted node to avoid memory leaks.
Answered by AI
Add your answer
Q2. Write an SQL query to find the nth highest salary.
Ans. 
SQL query to find the nth highest salary
• Use the ORDER BY clause to sort salaries in descending order

• Use the LIMIT and OFFSET clauses to skip the first n-1 highest salaries

• Combine the above steps in a single query to find the nth highest salary
Answered by AI
Add your answer
Q3. Can you explain the concepts of Object-Oriented Programming (OOP)?
Ans. 
OOP is a programming paradigm based on the concept of objects, which can contain data in the form of fields and code in the form of procedures.
• OOP focuses on creating objects that interact with each other to solve problems.

• Key concepts include encapsulation, inheritance, and polymorphism.

• Encapsulation involves bundling data and methods that operate on the data into a single unit.

• Inheritance allows classes to inherit at...read more
Answered by AI
Add your answer

Round duration - 60 minutes
Round difficulty - Easy

Was asked me about my favorite technologies, What i liked about Facebook. And asked me to design a cinema ticket reservation web site­ like the one satyam has.

Q1. 
Kth Largest Element Problem
Given an array containing N distinct positive integers and a number K, determine the Kth largest element in the array.
Example:
Input:
N = 6, K = 3, array = [2, 1, 5, 6, 3, ...read more
Ans. 
Find the Kth largest element in an array of distinct positive integers.
• Sort the array in non-increasing order and return the Kth element.

• Handle multiple test cases efficiently.

• Ensure all elements in the array are distinct.
Answered by AI
View 1 more answer
Q2. What are virtual functions?
Ans. 
Virtual functions are functions in a base class that are overridden in derived classes to achieve runtime polymorphism.
• Virtual functions are declared in a base class with the 'virtual' keyword.

• They are overridden in derived classes using the 'override' keyword.

• They allow a function to be called based on the runtime type of an object.

• Virtual functions enable dynamic binding and late binding in C++.

• Example: virtual void ...read more
Answered by AI
Add your answer
Q3. Design a Cinema Ticket Reservation System.
Ans. 
Design a Cinema Ticket Reservation System
• Use a database to store movie information, showtimes, and seat availability

• Allow users to search for movies, select showtimes, and choose seats

• Implement a payment system for ticket purchases

• Send confirmation emails with QR codes for ticket validation
Answered by AI
Add your answer
Q4. In how many attempts can you find a defective ball among 10 given balls using a two-pan balance scale?
Ans. 
You can find a defective ball among 10 given balls in 2 attempts using a two-pan balance scale.
• Divide the 10 balls into two groups of 5 each.

• Weigh the two groups on the balance scale.

• If one group is heavier, it contains the defective ball. If they are equal, the defective ball is in the remaining 5 balls.

• Divide the group of 5 balls with the defective one into two groups of 2 and 3 balls.

• Weigh the two groups on the bala...read more
Answered by AI
Add your answer

Round duration - 30 minutes
Round difficulty - Easy

HR round that lasted for about 30 minutes. The interviewer asked me questions to know more about me and a puzzle.

Q1. Can you tell me about your projects and your extracurricular activities?
Add your answer