Question

List of most asked stack and queue questions asked in interviews of FAANG/product based companies in 2020-2021 ?

Answer 1

Solve all these problems and you can clear any coding interview problem on this topic :-) 

Stack Implementation using a Linked List
Implement a stack using the queue data structure
Implement a queue using the stack data structure
Design a stack that returns the minimum element in constant time
Design a stack that returns a minimum element without using an auxiliary stack
Implement two stacks in a single array
Recursive solution to sort a stack
Reverse a stack using recursion
Reverse a string using a stack data structure
Check if an expression is balanced or not
Find duplicate parenthesis in an expression
Evaluate a postfix expressio
Decode a given sequence to construct a minimum number without repeated digits
Merging Overlapping Intervals
Convert an infix expression into a postfix expression
Find the next greater element for every element in a circular array
Find the next greater element for every array element
Find the previous smaller element for each array element
Reverse an array in C++
Longest Increasing Subsequence Problem
Find all elements in an array that are greater than all elements to their right
Iterative Implementation of Quicksort
Find all binary strings that can be formed from a wildcard pattern
Find the length of the longest balanced parenthesis in a string
Reverse text without reversing individual words
Reverse a string without using recursion
Inorder Tree Traversal
Preorder Tree Traversal
Postorder Tree Traversal
Check if two binary trees are identical or not
Find ancestors of a given node in a binary tree
Iteratively print the leaf to root path for every leaf node in a binary tree
Find preorder traversal of a binary tree from its inorder and postorder sequence
Construction of an expression tree
Print complete Binary Search Tree (BST) in increasing order
Depth First Search (DFS)
Check whether the leaf traversal of given binary trees is the same or not
Reverse level order traversal of a binary tree
Invert Binary Tree
Invert alternate levels of a perfect binary tree
Depth-First Search (DFS) vs Breadth-First Search (BFS)

 

 

 

 

 

Implement Stack from Scratch

Implement Queue from Scratch

Implement 2 stack in an array

find the middle element of a stack

Implement "N" stacks in an Array

Check the expression has valid or Balanced parenthesis or not.

Reverse a String using Stack

Design a Stack that supports getMin() in O(1) time and O(1) extra space.

Find the next Greater element

The celebrity Problem

Arithmetic Expression evaluation

Evaluation of Postfix expression

Implement a method to insert an element at its bottom without using any other data structure.

Reverse a stack using recursion

Sort a Stack using recursion

Merge Overlapping Intervals

Largest rectangular Area in Histogram

Length of the Longest Valid Substring

Expression contains redundant bracket or not

Implement Stack using Queue

Implement Stack using Deque

Stack Permutations (Check if an array is stack permutation of other)

Implement Queue using Stack

Implement "n" queue in an array

Implement a Circular queue

LRU Cache Implementationa

Reverse a Queue using recursion

Reverse the first “K” elements of a queue

Interleave the first half of the queue with second half

Find the first circular tour that visits all Petrol Pumps

Minimum time required to rot all oranges

Distance of nearest cell having 1 in a binary matrix

First negative integer in every window of size “k”

Check if all levels of two trees are anagrams or not.

Sum of minimum and maximum elements of all subarrays of size “k”.

Minimum sum of squares of character counts in a given string after removing “k” characters.

Queue based approach or first non-repeating character in a stream.

Next Smaller Element