K overlapping segment
Concepts Used: Stack. Difficulty Level: Medium. Problem Statement : Arnab is hosting a party but he has only k seats. Guest have come at different times and leave at different...
Max Rectangle
Concepts Used: DP/recursion and Stack. Difficulty Level: Hard. Problem Statement : Given a 2D binary matrix filled with 0’s and 1’s, find the largest rectangle containing all ones and print...
Samir String
Concepts Used: Stack. Difficulty Level: Easy. Problem Statement : Make the minimum number without repetition of the digits such that it follows the sequence given in the string. 'I' represents...
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...
Sort stack
Concepts Used: Stacks Difficulty Level: Easy. Problem Statement : Given a stack of integers, sort it in ascending order using another temporary stack. See original problem statement here Solving Approach:...
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: See original problem statement here Solving Approach : Bruteforce Approach: 1) We can...
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. See original problem statement here Example:...
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...
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...
Remove Kth element from Min Heap
Concepts Used : Heap Difficulty Level : Easy Problem Statement : Given an array containing N integers, our task is to: Create min-heap with 1 based indexing. Remove the element...
Print first K non-repeating characters of a string
Concepts Used: Heap Difficulty Level: Hard Problem Statement : Given a string str, find first K non-repeating characters in lexicographical order, if all the characters are repeating then print "Not...
Heap Sort
Concepts Used: Heap Difficulty Level: Easy Problem Statement : Given an array containing N integers, our task is to create a min-heap using the elements of the given array and...
Minimum Difference
Concepts Used Heap Difficulty Level: Hard Problem Statement : Given N sectors and two integers P and Q, our task is to find Q closest sectors to P sector. See...
Kth Largest element
In the realm of data structures, heaps stand out as an essential tool for efficient manipulation of priority-based information. One common problem encountered when dealing with heaps is finding the...
Kth Smallest Number
Concepts Used Heap Difficulty Level Easy Problem Statement : Given an array arr[ ] and a number K where K is smaller than the size of the array, the task...
Small String
Concepts Used Heap Difficulty Level Medium Problem Statement : Given a string str and an integer q. We have to generate a string S such that it is lexicographically smallest...
Maximum Books
Concepts Used Heap Difficulty Level Medium Problem Statement : We are given N book costs, and k amount of money. We need to find the maximum number of books we...
Prizes
Concepts Used Heap Difficulty Level Easy Problem Statement : Given N integers where a[i] represent that a[i]th student has won the ith competition. Print top Q students who have won...
Largest number smaller than or equal to N and digits in non-decreasing order
Concepts Used Strings Difficulty Level Medium Problem Statement (Simplified): For a number given to us, we have to print a number less than or equal to the given number, and...
Sort in a unique way
Concepts Used: Sorting Difficulty Level: Easy Problem Statement (Simplified): For a given array find the length of largest sorted sub-array in it, but if the current array is not sorted,...