30+ TCS Interview Questions and Answers

You are given an integer array ‘ARR’. You have to find the length of the shortest contiguous subarray such that, if you sort this subarray in ascending order, then the whole array will be sorted in asce...read more

You have been given an integer array/list(ARR) of size 'N'. It only contains 0s, 1s and 2s. Write a solution to sort this array/list.

Note :

Try to solve the problem in 'Single Scan'. ' Single Scan' r...read more

Given a string STR of length N. The task is to return the count of minimum characters to be added at front to make the string a palindrome.

For example, for the given string “de...read more

You are given a binary search tree of integers with N nodes. You are also given references to two nodes P and Q from this BST.

Your task is to find the lowest common ancestor(LCA) of these two given...read more

Ninja is given a binary search tree and an integer. Now he is given a particular key in the tree and returns its ceil value. Can you help Ninja solve the problem?

Note:

Ceil of an integer is the cl...read more

You are given a square matrix of non-negative integers 'MATRIX'. Your task is to rotate that array by 90 degrees in an anti-clockwise direction using constant extra space.

For example...read more

Given two binary trees T and S, check whether tree S has exactly the same structure and node values with a subtree of T, i.e., check if tree S is a subtree of the tree T.

A subtree of a t...read more

You have been given a number of stairs. Initially, you are at the 0th stair, and you need to reach the Nth stair. Each time you can either climb one step or two steps. You are...read more

Write a program to find the factorial of a number.

Factorial of n is:

n! = n * (n-1) * (n-2) * (n-3)....* 1

Output the factorial of 'n'. If it does not exist, output 'Error'.

Input format :...read more

For a given array/list of integers of size N, print the Next Greater Element(NGE) for every element. The Next Greater Element for an element X is the first element on the right side of X in ...read more

You are given an arbitrary binary tree consisting of N nodes, where each node is associated with a certain value, and two node values, a and b, you need to check if these nodes are...read more

You have been given a long type array/list 'ARR' of size 'N'. It represents an elevation map wherein 'ARR[i]' denotes the elevation of the 'ith' bar. Print the total amount of rainwater that ...read more

You have been given a grid containing some oranges. Each cell of this grid has one of the three integers values:

Value 0 - representing an empty cell.

Value 1 - representing a fresh orange.

...read more

You have a robot currently standing at the origin (0, 0) of a two-dimensional grid and facing north direction. You are given a sequence of moves for the robot in the form of a string of size 'N'. Y...read more

You are given an array ‘Arr’ consisting of ‘N’ distinct integers and a positive integer ‘K’. Find out Kth smallest and Kth largest element of the array. It is guaranteed...read more

Ninja recently studied odd and even numbers but he is more interested in even numbers.

He has an array ‘A’ containing ‘N’ integers. He will transform this array by moving all the even numbers at the ...read more

Pre-requisites: Anagrams are defined as words or names that can be formed by rearranging letters of another word. Such as "spar" can be formed by rearranging letters of "rasp". Hence, "spar" and "r...read more

Given a binary tree. Find and return the modulus of the difference between the sum of odd level nodes and the sum of even level nodes.

Input format:

The first line contains an integer 'T' which de...read more

You are given a positive integer ‘N’ denoting the number of tasks you need to finish. You can directly start performing any task, but some tasks have some prerequisites, i.e. to perform some ta...read more

You are given an N * N matrix of integers where each row and each column is sorted in increasing order. You are given a target integer 'X'. Find the position of...read more

Given a string ’S’ consisting of lower case English letters, you are supposed to return the longest palindromic substring of ‘S’.

Note that in case of more than one longest palindro...read more

Mr. X is a professional robber planning to rob houses along a street. Each house has a certain amount of money hidden. All houses along this street are arranged in a circle. That means the first hou...read more

Given an undirected graph of V vertices and E edges. Your task is to find all the bridges in the given undirected graph. A bridge in any graph is defined as an edge which, when removed, makes ...read more

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A discussion on Fn. dependencies

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What are the conditions for deadlock to occur?

How is Linked List Implemented in java and when will you prefer it over ArrayList

There are 12 coins. 11 of them have same weight and one is light in weight than others. We have a weighing balance. Find the minimum times we have to balance to find out the lighter one.

OOPs Questions,
Discussion on Singelton Design Pattern

Theory questions about OS . Multithreading, Scheduling Algorithms