Check if Given Number is power of 2.
Objective: Given a number, write a program to find if number is power of two. Example: N = 5 Output: false. N = 8 Output: true (23) N = 512 Output: true (29) Approach:...
Category: Top Companies
Find no of reverse pairs in an array which is sorted in two parts in O(N)
Objective: Given an array of integers A[] which is sorted in two parts (both parts are individually sorted), find no of reverse pairs means no of (i, j) pairs where i belongs to the...
Get the Sum of Digits in a number till it become a single digit
Objective – Given a number, Write a program to get the sum of digits in a number till it become a single digit. Example: N = 999 -> 9+9+9 = 27-> 2+7 = 9...
Check if given number is Prime – O(√N) Solution – Java Program
Objective: Given a number, write a program to check if the number is prime or not. Prime Number: A number is called a prime number when number is not divisible by 1 or by...
Print First N Prime Numbers – Java Code
Objective: Given a number N, write a program to print first N prime numbers. What is Prime number:?? A prime number (or a prime) is a natural number greater than 1 that cannot be...
Check if two Strings are equal without using built-in function – Java
Objective– Given two strings, find out if they are equal or not without using any built-in function (without using equals() function in java). Example: String x=’tutorial’ and String y=’tutorial’ are equal – true String...
Remove Vowels from a given String
Objective: Given a String, remove all the vowels from the string. What Are Vowels? The letters A, E, I, O, and U are called vowels. The other letters in the alphabet are called consonants....
Dijkstra’s – Shortest Path Algorithm (SPT) – Adjacency List and Min Heap – Java Implementation
Earlier we have seen the basics of Dijkstra algorithm. In this article we will see its implementation using adjacency list and Min Heap. We strongly recommend reading the following articles Dijkstra algorithm and how...
Swap two numbers using Bitwise XOR Operator
Objective– Given two numbers, swap both the numbers using XOR operators. Example: X = 4, Y = 8 Output: X = 8, Y= 4 Approach: XOR operator There are many ways to swap two...
Replace all vowels with next consonant in a given string
Objective: Given a string, write an algorithm to replace all the vowels with next consonant, and if last alphabet is vowel, remove it. Example: String input: “abcdefg” Output: “bbcdffg” String input: “aaaabccceee” Output: “bbbbbccc”...
Convert Number to base 3 String Representation
Objective: Given a number convert it to base 3 representation. Example: N = 35 Base 3 representation: 1022 N = 50 Base 3 representation: 1212 Approach: Till the number is greater than 0, keep...
Graph – Find Cycle in Undirected Graph using Disjoint Set (Union-Find)
Objective: Given a graph, check if the graph contains a cycle using disjoint set. Note: Disjoint-set data structure, also called a union–find data structure or merge–find set. Example: Earlier in Detect Cycle in Undirected Graph using DFS we...
Graph – Count all paths between source and destination
Objective: Given a graph, source vertex and destination vertex. Write an algorithm to count all possible paths between source and destination. Condition: Graph does not contain any cycle. This problem also known as “paths...
Graph – Detect Cycle in a Directed Graph using colors
Objective: Given a directed graph write an algorithm to find out whether graph contains cycle or not. Example: Approach: Graph contains cycle if there are any back edges. There are two types of back...
Graph – Detect Cycle in Undirected Graph using DFS
Objective: Given undirected graph write an algorithm to find out whether graph contains cycle or not. Example: Approach: Earlier we have seen how to find cycles in directed graphs. In this article we will...