Stack Interview Questions

Rank

#716HardFrequency: 100%

Max Stack

Linked List Stack Design Doubly-Linked List Ordered Set

Rank

#71MediumFrequency: 100%

Simplify Path

Asked at Oracle

Rank

#227MediumFrequency: 96%

Basic Calculator II

Math String Stack

Rank

#364MediumFrequency: 88%

Nested List Weight Sum II

Stack Depth-First Search Breadth-First Search

Rank

#42HardFrequency: 74%

Trapping Rain Water

Array Two Pointers Dynamic Programming Stack Monotonic Stack

Rank

#224HardFrequency: 73%

Basic Calculator

Asked at DoorDash

Math String Stack Recursion

Rank

#20EasyFrequency: 71%

Valid Parentheses

Asked at Apple

Rank

#957MediumFrequency: 66%

Minimum Add to Make Parentheses Valid

String Stack Greedy

Rank

#758MediumFrequency: 64%

Convert Binary Search Tree to Sorted Doubly Linked List

Linked List Stack Tree Depth-First Search Binary Search Tree Binary Tree Doubly-Linked List

#10

Rank

#1909MediumFrequency: 64%

Buildings With an Ocean View

#11

Rank

#155MediumFrequency: 55%

Min Stack

Stack Design

#12

Rank

#1128EasyFrequency: 55%

Remove All Adjacent Duplicates In String

#13

Rank

#114MediumFrequency: 53%

Flatten Binary Tree to Linked List

Linked List Stack Tree Depth-First Search Binary Tree

#14

Rank

#232EasyFrequency: 51%

Implement Queue using Stacks

Stack Design Queue

#15

Rank

#173MediumFrequency: 51%

Binary Search Tree Iterator

Stack Tree Design Binary Search Tree Binary Tree Iterator

#16

Rank

#234EasyFrequency: 48%

Palindrome Linked List

Linked List Two Pointers Stack Recursion

#17

Rank

#84HardFrequency: 45%

Largest Rectangle in Histogram

#18

Rank

#394MediumFrequency: 42%

Decode String

String Stack Recursion

#19

Rank

#739MediumFrequency: 42%

Daily Temperatures

#20

Rank

#735MediumFrequency: 37%

Asteroid Collision

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Array Stack Simulation

#21

Rank

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Stack Interview Questions

Master 21 stack problems frequently asked in technical interviews. These questions test your understanding of stackconcepts and are essential for coding interview success.

Total Problems

Easy

Medium

Hard

Minimum Remove to Make Valid Parentheses

Rank

#716HardFrequency: 100%

Max Stack

Linked List Stack Design Doubly-Linked List Ordered Set

Rank

#71MediumFrequency: 100%

Simplify Path

Asked at Oracle

Rank

#227MediumFrequency: 96%

Basic Calculator II

Math String Stack

Rank

#364MediumFrequency: 88%

Nested List Weight Sum II

Stack Depth-First Search Breadth-First Search

Rank

#42HardFrequency: 74%

Trapping Rain Water

Array Two Pointers Dynamic Programming Stack Monotonic Stack

Rank

#224HardFrequency: 73%

Basic Calculator

Asked at DoorDash

Math String Stack Recursion

Rank

#20EasyFrequency: 71%

Valid Parentheses

Asked at Apple

Rank

#957MediumFrequency: 66%

Minimum Add to Make Parentheses Valid

String Stack Greedy

Rank

#758MediumFrequency: 64%

Convert Binary Search Tree to Sorted Doubly Linked List

Linked List Stack Tree Depth-First Search Binary Search Tree Binary Tree Doubly-Linked List

#10

Rank

#1909MediumFrequency: 64%

Buildings With an Ocean View

#11

Rank

#155MediumFrequency: 55%

Min Stack

Stack Design

#12

Rank

#1128EasyFrequency: 55%

Remove All Adjacent Duplicates In String

#13

Rank

#114MediumFrequency: 53%

Flatten Binary Tree to Linked List

Linked List Stack Tree Depth-First Search Binary Tree

#14

Rank

#232EasyFrequency: 51%

Implement Queue using Stacks

Stack Design Queue

#15

Rank

#173MediumFrequency: 51%

Binary Search Tree Iterator

Stack Tree Design Binary Search Tree Binary Tree Iterator

#16

Rank

#234EasyFrequency: 48%

Palindrome Linked List

Linked List Two Pointers Stack Recursion

#17

Rank

#84HardFrequency: 45%

Largest Rectangle in Histogram

#18

Rank

#394MediumFrequency: 42%

Decode String

String Stack Recursion

#19

Rank

#739MediumFrequency: 42%

Daily Temperatures

#20

Rank

#735MediumFrequency: 37%

Asteroid Collision