20+ Interview Questions and Answers

Q1. Minimum Cost to Destination

You have been given an N*M matrix where there are 'N' rows and 'M' columns filled with '0s' and '1s'.

'1' means you can use the cell, and '0' means the cell is blocked. You can move ...read more

Q2. Fix BST

Given a Binary Search Tree, where exactly two nodes of the same tree were swapped by mistake. The task is to restore or fix the BST, without changing its structure.

A binary search tree (BST), also calle...read more

Q3. Water Jug Problem

You are given two water jugs with capacities X and Y litres respectively. Both the jugs are initially empty. There is an infinite amount of water supply available. The jugs do not have markings...read more

Q4. Ways To Make Coin Change

You are given an infinite supply of coins of each of denominations D = {D0, D1, D2, D3, ...... Dn-1}. You need to figure out the total number of ways W, in which you can make a change fo...read more

Q5. Count Ways To Travel Triangular Pyramid

Bob has been given a triangular pyramid with its vertices marked as ‘O’, ‘X’, ‘Y’ and ‘Z’ and provided with another integer ‘N’. In a single step, Bob can go to any adjace...read more

Q6. Zig-Zag String

You are given a string ‘STR’ of size ‘N’ and an integer ‘M’ (the number of rows in the zig-zag pattern of ‘STR’). Your task is to return the string formed by concatenating all ‘M’ rows when string...read more

Q7. Largest Island

You have been given a non-empty grid consisting of only 0s and 1s. You have to find the maximum area of an island in the given grid.

An island is a group of 1s (representing land) connected horizo...read more

Q8. Position of Right Most Set Bit

You are given a number N. You need to return the position of the rightmost set bit.

For example:

If the given number is 10 with the binary representation: 1010 The rightmost set b...read more

Q9. Maximum Profit

Mukesh is a hard worker and has a good running business. He has a list of profits he made in the last ‘N’ days. Mukesh wants to know what maximum profit he made in the few consecutive days. More P...read more

Q10. Maximum sum such that no two elements are adjacent

You are given an array/list of ‘N’ integers. You are supposed to return the maximum sum of the subsequence with the constraint that no two elements are adjacent...read more

Q11. Number Of Pairs With Given Sum

You have been given an integer array/list(arr) and a number 'Sum'. Find and return the total number of pairs in the array/list which when added, results equal to the 'Sum'.

Note:

G...read more

Q12. Word Search

You are given a two-dimensional grid having 'N' rows and 'M' columns, consisting of upper case characters. You are also given a word 'WORD'. You have to find the number of occurrences of that word i...read more

Q13. Pythagorean Triplet

You are given an array of n integers (a1, a2,....,an), you need to find if the array contains a pythagorean triplet or not.

An array is said to have a pythagorean triplet if there exists thre...read more

Q14. Top View of Binary Tree

You are given a Binary Tree of integers. You are supposed to return the top view of the given binary tree. The Top view of the binary tree is the set of nodes that are visible when we see...read more

Q15. Boundary Traversal

You have been given a binary tree of integers. Your task is to print the boundary nodes of this binary tree in Anti-Clockwise direction starting from the root node.

NOTE:

The boundary nodes of...read more

Q16. Possible to form a triangle

You are given an integer of array/list 'ARR' of length ‘N. You are supposed to return true if it is possible to construct at least one non-degenerate triangle using values of array/li...read more

Q17. Implement Stack with Linked List

You need to implement the Stack data structure using a Singly Linked List.

Create a class named 'Stack' which supports the following operations(all in O(1) time):

getSize: Retur...read more

Q18. Running Median

You are given a stream of 'N' integers. For every 'i-th' integer added to the running list of integers, print the resulting median.

Print only the integer part of the median.

Input Format :

The fi...read more

Q19. Rotate Matrix right by K times

You have been given a matrix ‘MAT’ of size 'N' * 'M' (where 'N' and 'M' denote the number of rows and columns respectively) and a positive integer ‘K’. Your task is to rotate the m...read more

Q20. Rat In A Maze

You are given a starting position for a rat which is stuck in a maze at an initial point (0, 0) (the maze can be thought of as a 2-dimensional plane). The maze would be given in the form of a squar...read more

Q21. Sum Tree

For a given binary tree, convert it to its sum tree. That is, replace every node data with sum of its immediate children, keeping leaf nodes 0. Finally, return its preorder.

For example:

The input for t...read more

Q22. Technical Questions

Questions on DBMS, Os, Puzzles, Your projects.

What is indexing?

CPU Scheduling algos.

Q23. Given a 2D matrix having 0s and 1s, each row is sorted. Find the row having the maximum number of consecutive ones in the matrix.

Q24. Given N documents and a set of keywords was given, you have to retrieve document having highest frequency of those keywords first and then others.

Q25. OS Questions

Core concepts like deadlock, semaphore, memory management

Q26. DBMS Question

Core concepts like indexing