Detect Cycle
Concepts Used Breadth First Search, Disjoint Set Difficulty Level Easy Problem Statement : Given an undirected graph, print Yes if a cycle is present in the graph else print No....
Hop Digits
Concepts Used Breadth First Search Difficulty Level Hard Problem Statement : Given a string , we are standing at the starting point and we have to reach end in minimum...
Next Greater Element
Concepts Used: Stacks. Difficulty Level: Medium. Problem Statement : Arnab is standing in a queue and he is irritated by the tall man standing after him, as he is obstructing...
Longest Path
Concepts Used Breadth First Search Difficulty Level Medium Problem Statement : Given an unweighted, undirected tree print the length of the longest path Solution Approach : Introduction : Path lenght...
Maximum Edges
Concepts Used Depth First Search, Disjoint Set Difficulty Level Medium Problem Statement : Given N number of vertices, M number of edges and relation between them to form an undirected...
Sort stack
Concepts Used: Stacks Difficulty Level: Easy. Problem Statement : Given a stack of integers, sort it in ascending order using another temporary stack. Solving Approach: Approach 1 ( Using temporary...
Remove all adjacent duplicates
Concepts Used Stack Difficulty Level Easy Problem Statement : Given a string str of lowercase letters, a duplicate removal consists of choosing two adjacent and equal letters, and removing them....
Get Minimum Element from Stack
Get minimum element from stack is a common problem in computer science. A stack is a data structure that follows the Last-In-First-Out (LIFO) principle, where elements are added and removed...
Beach House
Concepts Used: Stack. Difficulty Level: Hard. Problem Statement : Nishant wants to buy a plot of land, which faces the beach. He will buy only a rectangular plot. So he...
One more GCD sum
Concepts Used Mathematics Difficulty Level Hard Problem Statement (Simplified): Calculate the sum for a given number n: Solving Approach : Bruteforce Approach: 1) We can use a double loop to...
Beautiful Bracket String
Concepts Used: Stack Difficulty Level: Medium. Problem Statement : Find the minimum number of replacements required to make the given string of braces balanced. Example: Input: }{ {}{}{} {{{} Output:...
Small Group
Concepts Used Heap Difficulty Level Hard Problem Statement : Given an array of N integers, we want to know whether it is possible to divide the students into contiguous groups...
Fascinating Multiple Number
Concepts Used Heap Difficulty Level Medium Problem Statement : Given an array A of size N, we have to perform following operations, untill only one integer remains (N-1 times) :...
Swap Sum
Concepts Used Heap Difficulty Level Medium Problem Statement : We are given N elements with an integer S. We want to find such a sub-array that has the maximum possible...
Binary Queue
Concepts Used: Queues. Difficulty Level: Medium. Problem Statement : Given a number N, print all possible binary numbers with decimal values from 1 to N, but the catch is you...
Enqueue and Dequeue in Data Structure
The queue is a linear data structure that follows the First-In-First-Out (FIFO) principle. Since queues maintain the order of insertion of elements and also remove elements in the same order...
Print first Non-repeating character in a string
Concepts Used: Hashing. Difficulty Level: Easy. Problem Statement : You are given a string str consisting of lowercase Latin letters. Find the first non-repeating character in str. Note: You have...
Compile Code
Concepts Used: Stacks. Difficulty Level: Medium. Problem Statement : Given a string of open angular bracket ‘<‘ and closed bracket ‘>’. The task is to find the length of longest...
Edge Divide(C, JAVA CODE NOT INCLUDED)
Concepts Used Depth First Search Difficulty Level Hard Problem Statement : Given an undirected connected graph, you must find all the edges which when removed divide the graph. Solution Approach...
Arrogant Students
Concepts Used: Stacks Difficulty Level: Hard. Problem Statement : Sachin is teaching a group of N students. Now every student has an arrogance level. He make all the N students...
Files
Concepts Used Basic operations of stack. Difficulty Level: Hard. Problem Statement : Nikhil now got a job. His task is to evaluate files. His boss comes and puts a file...
Majority Votes
CONCEPTS USED: Hashing DIFFICULTY LEVEL: Medium PROBLEM STATEMENT(SIMPLIFIED): Given an array of size N, which contains the voting ID's of students that have stood up for the elections for class...
Find Mountain Top
CONCEPTS USED: Binary Search DIFFICULTY LEVEL: Medium PROBLEM STATEMENT(SIMPLIFIED): Given an array A of N integers, such that till a point these integers are strictly increasing and after that strictly...
Fair Distribution of Chocolates
CONCEPTS USED: Binary Search DIFFICULTY LEVEL: Hard PROBLEM STATEMENT(SIMPLIFIED): Given number of chocolates in N different bags and M children. Every kid will get some consecutive bags. The task is...
Zigzag String from the Character on Rows
Problem Statement (Simplified): For a given string S and number of rows R, we have to arrange each character on rows in a vertical zigzag format, and then print values...
Missing in AP
CONCEPTS USED: Binary Search DIFFICULTY LEVEL: Medium PROBLEM STATEMENT(SIMPLIFIED): Given an array A, such that it is arranged in an Arithmetic Progression, but one element from this A.P. is missing,...
Balancing the Magnets
CONCEPTS USED: Binary Search DIFFICULTY LEVEL: Hard PROBLEM STATEMENT(SIMPLIFIED): Given an array of N size containing the positions of N magnets. These magnets are repelling each other. The magnets on...
Transition Point
CONCEPTS USED: Binary Search DIFFICULTY LEVEL: Easy PROBLEM STATEMENT(SIMPLIFIED): Given a sorted array of 0's and 1's of size N, find the first occurrence of 1 if present else return...
Next Greater Same Digit
CONCEPTS USED: Searching DIFFICULTY LEVEL: Hard PROBLEM STATEMENT(SIMPLIFIED): Given a number N, find the smallest number that has same set-of-digits as N and is greater than N. If N is...
Smallest Number
CONCEPTS USED: Hashing DIFFICULTY LEVEL: Easy PROBLEM STATEMENT(SIMPLIFIED): Given an array A with N integers and an integer K, print the smallest number in the array which occurs exactly K...