## Sieve of Eratosthenes

Sieve of Eratosthenes is an algorithm in which we find out the prime numbers less than N. Here N is an integer value. This is an efficient method to find out the prime numbers to a limit. By using this we can find out the prime numbers till 10000000. Here …

## Guess The Word

Guess The Word is an interactive problem. An interactive problem means the data which is given to us is not predetermined. We can print values or call the specific function to interact or get more information regarding the solution. After each step, we also need to FLUSH the buffer to …

## New 21 Game

New 21 Game is a problem that is based on the card game “21”. The problem statement of this problem is simple. We are initially having 0 points. If the value of our current points is less than K points then we draw numbers. During each draw we gain an …

## Partition Equal Subset Sum

Partition Equal Subset Sum is a problem in which we have given an array of positive numbers. We have to find out that can we divide it into two subsets such that the sum of elements in both sets is the same. Here it’s not necessary that the number of …

## Subarray Sum Equals k

Given an integer array and an integer k. Find total number of contiguous subarrays of given array whose sum of elements is equal to k. Example Input 1: arr[] = {5,0,5,10,3,2,-15,4} k = 5 Output: 7 Input 2: arr[] = {1,1,1,2,4,-2} k = 2 Output: 4 Explanation : consider example-1 …

## Serialize and Deserialize Binary Tree

We have given a binary tree containing N number of nodes where each node has some value. We need to serialize and deserialize the binary tree. Serialize The process of storing a tree in a file without disturbing its structure is called serialization. DeserializeSerialize and Deserialize Binary Tree The process …

## Fibonacci numbers

Fibonacci numbers are the numbers that form the series called Fibonacci series and are represented as Fn. The first two Fibonacci numbers are 0 and 1 respectively i.e. F0=0 and F1=1. Starting from the third Fibonacci number each Fibonacci number is the sum of its previous two numbers in the …

## Coin Change Problem

Coin Change Problem – Given some coins of different values c1, c2, … , cs (For instance: 1,4,7….). We need an amount n. Use these given coins to form the amount n. You can use a coin as many times as required. Find the total number of ways in which …

## Reverse String Without Temporary Variable

Problem Statement In the “Reverse String Without Temporary Variable” problem we have given a string “s”. Write a program to reverse this string without using any extra variable or space. Input Format The first line containing the given string “s”. Output Format Print the string which is reverse of the …