Next Smaller Element
Problem Statement: YOu are given an unsorted array, you need to find the next smaller element for all the elements. Next smaller element for…
Reverse the first “K” elements of a queue
Problem Statement: You are given a queue and an element k, you need to reverse the first ‘k’ elements in the queue. Example Input:…
Queue Reversal
Problem Statement: Given a queue, you need to reverse it. Solution This problem can be solved in 2 different methods. Method 1: Using stack.…
Stack: Check if a stack is a permutation of another stack
Problem Statement: You are given 2 array, check one array is permutation of another array. Example Input : First array: 1, 2, 3 Second array:…
Implement Stack using Queues
Problem Statement: You need to create stack data structure using only queue data structure. Solution As we know that for stack insertion and…
Stack: Expression contains redundant bracket or not
Problem Statement: You are given an expression in the form of a string. You need to check if the string has redundant brackets. Example Input:…
Stack: Length of the longest valid substring
Problem Statement: You are given a string, you need to find the length of longest valid parenthesis. Example Input : ((() Output : 2 Solution…
Largest Rectangular Area in a Histogram
Problem Statement: You are given an array that represents a bar in a histogram. You need to find out the largest rectangle that can be made…
Sort a stack
Problem Statement: You are given a stack, you need to sort it. Solution This problem can be solved in 2 different methods: 1. Sorting using…
Stack: Reverse a stack using recursion
Problem Statement: You are given a stack, you need to reverse the stack without using while, for. You need to reverse using recursion.…