Stack: Check if a queue can be sorted into another queue using a stack
Problem Statement: You are given a queue having first n natural numbers. You need to check if the given queue elements can be arranged in…
Stack: Check if the expression contains redundant bracket or not
Problem Statement: You are given a string, you need to check if the string contains redundant parenthesis or not Example: Input : ((a + b))…
Stack: Check if stack elements are pairwise consecutive
Problem Statement: Given a stack of integers, you need to check if the stack is pairwise consecutive or not. The pairs can be increasing and…
Stack: Sort a stack using recursion
Problem Statement: Sort a stack using recursion. Solution Explanation: Remove the top element, recursively sort the remaining elements. Take a…
Stack: Sort a stack using a temporary stack
Problem Statement: You are given integers in a stack. You need to sort it in ascending order using another stack. Example: Input: [5, 3, 4, 2,…
Stack: Reversing the first K elements of a Queue
Problem Statement: You are given a queue and integer k. Your task is to reverse the order of the first k element of the queue. Leaving the…
Stack: Given an array, you need to find the previous greater element
Problem Statement: Given an array of distinct elements, you need to find the previous greater element. If there is no greater element, return…
Stack: Nearest smaller numbers on left side in an array
Problem Statement: Given an array, you need to find the nearest smaller number for every element on its left side. Example: Input : [1, 6, 0,…
Stack: Prefix to postfix conversion
Problem Statement: Prefix expression: *+AB-CD is a prefix expression. Postfix expression: AB+CD-* Solution Explanation: Read the prefix…
Stack: Prefix to infix conversion
Problem Statement: Prefix expression: *+AB-CD is a prefix expression. Infix expression: ((A+B)*(C-D)) is an Infix expression Solution…