Top 250 DSA Checklist

A comprehensive set of 250 interview questions covering all core DSA patterns.

0 / 250 Completed 0%

2D Dynamic Programming

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Status Problem Difficulty Companies
Unique Paths Medium
AmazonGoogleFacebookMicrosoftBloomberg
Longest Common Subsequence Medium
GoogleAmazonFacebookMicrosoftBloomberg
Last Stone Weight II Medium
GoogleAmazon
Unique Paths II Medium
GoogleAmazonMicrosoft
Minimum Path Sum Medium
GoogleAmazonMicrosoft
Best Time to Buy and Sell Stock with Cooldown Medium
GoogleAmazonMicrosoftMetaApple
Coin Change II Medium
GoogleAmazonMicrosoftMeta
Target Sum Medium
GoogleAmazonMicrosoftMeta
Interleaving String Medium
GoogleAmazonMicrosoft
Stone Game Medium
GoogleAmazon
Stone Game II Medium
GoogleAmazon
Longest Increasing Path in a Matrix Hard
GoogleAmazonMicrosoftMeta
Distinct Subsequences Hard
GoogleAmazonMicrosoft
Edit Distance Medium
GoogleAmazonMicrosoftMetaApple
Burst Balloons Hard
GoogleAmazonMicrosoft
Regular Expression Matching Hard
GoogleAmazonMicrosoftMetaApple

Arrays & Hashing

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Status Problem Difficulty Companies
Two Sum Easy
AmazonGoogleMicrosoftMetaAppleBloomberg
Contains Duplicate Easy
AmazonGoogleMicrosoftBloombergApple
Valid Anagram Easy
AmazonGoogleMicrosoftMetaBloomberg
Group Anagrams Medium
AmazonGoogleMetaMicrosoftBloomberg
Top K Frequent Elements Medium
AmazonGoogleMetaMicrosoftApple
Product of Array Except Self Medium
AmazonMetaMicrosoftAppleGoogle
Longest Consecutive Sequence Medium
AmazonGoogleMetaMicrosoftAdobe
Encode and Decode Strings Medium
GoogleFacebookAmazonMicrosoft
Concatenation of Array Easy
GoogleAdobeApple
Longest Common Prefix Easy
AmazonGoogleFacebookMicrosoftApple
Remove Element Easy
GoogleAdobeAmazon
Majority Element Easy
AmazonGoogleMicrosoftMeta
Design HashSet Easy
GoogleMicrosoftAmazonApple
Design HashMap Easy
MicrosoftGoogleAmazonApple
Sort an Array Medium
GoogleMicrosoftAmazonAdobe
Sort Colors Medium
MicrosoftGoogleAmazonMeta
Range Sum Query 2D Immutable Medium
GoogleFacebookAmazonMicrosoft
Valid Sudoku Medium
GoogleUberAmazonMicrosoft
Best Time to Buy And Sell Stock II Medium
AmazonGoogleMicrosoftMeta
Majority Element II Medium
GoogleAmazonMicrosoft
Subarray Sum Equals K Medium
MetaGoogleAmazonMicrosoft
First Missing Positive Hard
GoogleAmazonMicrosoftMeta
Contains Duplicate II Easy
GoogleAmazonMicrosoft
Maximum Frequency Stack Hard
GoogleAmazonMicrosoftMeta
Time Based Key Value Store Medium
GoogleAmazonMicrosoftMetaNetflix
Copy List With Random Pointer Medium
MetaGoogleAmazonMicrosoft
LRU Cache Medium
GoogleAmazonMicrosoftMetaApple
LFU Cache Hard
GoogleAmazonMicrosoftMetaApple
Maximum Sum Circular Subarray Medium
GoogleAmazonMicrosoft
Gas Station Medium
AmazonGoogleMicrosoftMetaApple
Hand of Straights Medium
GoogleAmazon
Candy Hard
GoogleAmazonMicrosoftApple

Backtracking

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Status Problem Difficulty Companies
Combination Sum Medium
GoogleAmazonFacebookMicrosoftAdobe
Design Add and Search Words Data Structure Medium
AmazonGoogleFacebookMicrosoft
Word Search Medium
AmazonGoogleFacebookMicrosoftBloomberg
Word Search II Hard
GoogleAmazonMicrosoftUberApple
Generate Parentheses Medium
GoogleAmazonMicrosoftMeta
Subsets Medium
AmazonMicrosoftGoogleMetaApple
Combination Sum II Medium
AmazonMicrosoftGoogle
Permutations Medium
AmazonMicrosoftGoogleMetaBloomberg
Subsets II Medium
AmazonGoogleMicrosoft
Permutations II Medium
AmazonMicrosoftApple
Letter Combinations of a Phone Number Medium
AmazonGoogleMetaMicrosoftApple
Palindrome Partitioning Medium
AmazonGoogleMicrosoftApple
N-Queens Hard
AmazonGoogleMicrosoftMeta
N-Queens II Hard
AmazonGoogle
Sum of All Subset XOR Totals Easy
Amazon
Combinations Medium
AmazonGoogleMicrosoft
Matchsticks to Square Medium
AmazonGoogle
Partition to K Equal Sum Subsets Medium
AmazonGoogleMicrosoft
Word Break II Hard
AmazonGoogleMicrosoftMeta
Reconstruct Itinerary Hard
GoogleAmazon

1D Dynamic Programming

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Status Problem Difficulty Companies
Climbing Stairs Easy
AmazonGoogleFacebookMicrosoftBloomberg
House Robber Medium
GoogleAmazonFacebookMicrosoftBloomberg
House Robber II Medium
GoogleAmazonFacebookMicrosoft
Longest Palindromic Substring Medium
AmazonGoogleFacebookMicrosoftBloomberg
Palindromic Substrings Medium
FacebookGoogleAmazonMicrosoftBloomberg
Decode Ways Medium
GoogleAmazonFacebookMicrosoftBloomberg
Coin Change Medium
GoogleAmazonFacebookMicrosoftBloomberg
Maximum Product Subarray Medium
AmazonGoogleFacebookMicrosoftBloomberg
Word Break Medium
GoogleAmazonFacebookMicrosoftBloomberg
Longest Increasing Subsequence Medium
GoogleAmazonFacebookMicrosoftBloomberg
Extra Characters in a String Medium
GoogleAmazon
House Robber III Medium
GoogleAmazonMicrosoftMetaApple
Min Cost Climbing Stairs Easy
AmazonGoogleMicrosoft
N-th Tribonacci Number Easy
Amazon
Partition Equal Subset Sum Medium
AmazonGoogleMicrosoftMetaBloomberg
Combination Sum IV Medium
AmazonGoogleMicrosoftMeta
Perfect Squares Medium
GoogleAmazonMicrosoftMeta
Integer Break Medium
GoogleAmazonMicrosoft
Stone Game III Hard
GoogleAmazon
Last Stone Weight II Medium
GoogleAmazon
Coin Change II Medium
GoogleAmazonMicrosoftMeta
Target Sum Medium
GoogleAmazonMicrosoftMeta

Bit Manipulation

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Status Problem Difficulty Companies
Number of 1 Bits Easy
GoogleAmazonFacebookMicrosoftApple
Counting Bits Easy
GoogleAmazonFacebookMicrosoftBloomberg
Reverse Bits Easy
GoogleAmazonFacebookMicrosoftApple
Missing Number Easy
GoogleAmazonFacebookMicrosoftBloomberg
Sum of Two Integers Medium
GoogleAmazonFacebookMicrosoftBloomberg
Single Number Easy
AmazonGoogleMicrosoftMetaApple
Add Binary Easy
FacebookAmazonGoogle
Reverse Integer Medium
AmazonGoogleMicrosoftApple
Bitwise AND of Numbers Range Medium
AmazonGoogle
Minimum Array End Medium
Google

Graphs

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Status Problem Difficulty Companies
Number of Islands Medium
AmazonGoogleFacebookMicrosoftBloomberg
Clone Graph Medium
GoogleFacebookAmazonMicrosoft
Pacific Atlantic Water Flow Medium
GoogleAmazonFacebookMicrosoft
Course Schedule Medium
GoogleAmazonFacebookMicrosoftBloomberg
Number of Connected Components in an Undirected Graph Medium
AmazonGoogleFacebookMicrosoft
Graph Valid Tree Medium
GoogleAmazonFacebookMicrosoft
Alien Dictionary Hard
GoogleAmazonFacebookMicrosoftAirbnb
Max Area of Island Medium
AmazonGoogleMicrosoftMeta
Rotting Oranges Medium
AmazonGoogleMicrosoftMetaBloomberg
Walls and Gates Medium
MetaGoogleAmazon
Surrounded Regions Medium
AmazonGoogleMicrosoft
Open the Lock Medium
AmazonGoogle
Redundant Connection Medium
AmazonGoogleMicrosoft
Accounts Merge Medium
AmazonGoogleMetaMicrosoft
Evaluate Division Medium
AmazonGoogleMicrosoftMeta
Word Ladder Hard
AmazonGoogleMicrosoftBloomberg
Minimum Height Trees Medium
AmazonGoogleMicrosoft
Island Perimeter Easy
AmazonGoogleBloomberg
Verifying an Alien Dictionary Easy
AmazonGoogleMetaApple
Find the Town Judge Easy
AmazonGoogle
Course Schedule II Medium
AmazonGoogleMicrosoftMetaApple
Course Schedule IV Medium
AmazonGoogle
Jump Game VII Medium
GoogleAmazon
Path With Minimum Effort Medium
GoogleAmazon
Network Delay Time Medium
GoogleAmazonMicrosoft
Reconstruct Itinerary Hard
GoogleAmazon
Min Cost to Connect All Points Medium
GoogleAmazonMicrosoft
Swim in Rising Water Hard
GoogleAmazon
Cheapest Flights Within K Stops Medium
GoogleAmazonMicrosoft
Find Critical and Pseudo-Critical Edges in Minimum Spanning Tree Hard
GoogleAmazon
Build a Matrix With Conditions Hard
Google
Greatest Common Divisor Traversal Hard
GoogleAmazon
Longest Increasing Path in a Matrix Hard
GoogleAmazonMicrosoftMeta

Binary Search

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Status Problem Difficulty Companies
Find Minimum in Rotated Sorted Array Medium
AmazonGoogleMicrosoftMetaApple
Search in Rotated Sorted Array Medium
AmazonGoogleMetaMicrosoftApple
Search a 2D Matrix Medium
GoogleAmazonMicrosoftMeta
Find K Closest Elements Medium
GoogleAmazonMicrosoftMeta
Binary Search Easy
GoogleAmazonMicrosoftMeta
Search Insert Position Easy
GoogleAmazonMicrosoft
Guess Number Higher Or Lower Easy
GoogleAmazonMicrosoft
Sqrt(x) Easy
GoogleAmazonMicrosoftMeta
Koko Eating Bananas Medium
GoogleAmazonMicrosoftMeta
Capacity to Ship Packages Within D Days Medium
GoogleAmazonMicrosoftMeta
Search In Rotated Sorted Array II Medium
GoogleAmazonMicrosoft
Time Based Key Value Store Medium
GoogleAmazonMicrosoftMetaNetflix
Split Array Largest Sum Hard
GoogleAmazonMicrosoftMeta
Median of Two Sorted Arrays Hard
GoogleAmazonMicrosoftMetaApple
Find in Mountain Array Hard
GoogleAmazonMicrosoft

Heap & Priority Queue

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Status Problem Difficulty Companies
Find Median from Data Stream Hard
GoogleAmazonMicrosoftFacebookBloomberg
Merge K Sorted Lists Hard
AmazonGoogleMetaMicrosoftBloomberg
Top K Frequent Elements Medium
AmazonGoogleMetaMicrosoftApple
K Closest Points to Origin Medium
AmazonGoogleMetaMicrosoftUber
Kth Largest Element in an Array Medium
AmazonGoogleMetaMicrosoftAppleBloomberg
Task Scheduler Medium
AmazonGoogleMicrosoftMetaApple
Design Twitter Medium
AmazonMicrosoftMeta
Reorganize String Medium
AmazonGoogleMicrosoftMeta
Longest Happy String Medium
AmazonGoogle
Car Pooling Medium
AmazonGoogleLyft
IPO Hard
AmazonGoogle
Single Threaded CPU Medium
AmazonGoogle
Meeting Rooms III Hard
GoogleAmazonMicrosoft
Minimum Interval to Include Each Query Hard
GoogleAmazon
Kth Largest Element In a Stream Easy
GoogleAmazonMicrosoftMeta
Last Stone Weight Easy
GoogleAmazonMicrosoftMeta
Path With Minimum Effort Medium
GoogleAmazon
Network Delay Time Medium
GoogleAmazonMicrosoft
Min Cost to Connect All Points Medium
GoogleAmazonMicrosoft
Swim in Rising Water Hard
GoogleAmazon

Greedy

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Status Problem Difficulty Companies
Maximum Subarray Medium
AmazonGoogleFacebookMicrosoftBloomberg
Jump Game Medium
AmazonGoogleFacebookMicrosoftBloomberg
Best Time to Buy And Sell Stock II Medium
AmazonGoogleMicrosoftMeta
Boats to Save People Medium
GoogleAmazonMicrosoft
Task Scheduler Medium
AmazonGoogleMicrosoftMetaApple
Reorganize String Medium
AmazonGoogleMicrosoftMeta
Longest Happy String Medium
AmazonGoogle
Car Pooling Medium
AmazonGoogleLyft
IPO Hard
AmazonGoogle
Lemonade Change Easy
Amazon
Maximum Sum Circular Subarray Medium
GoogleAmazonMicrosoft
Longest Turbulent Subarray Medium
GoogleAmazon
Jump Game II Medium
AmazonGoogleMicrosoftMetaApple
Jump Game VII Medium
GoogleAmazon
Gas Station Medium
AmazonGoogleMicrosoftMetaApple
Hand of Straights Medium
GoogleAmazon
Dota2 Senate Medium
GoogleAmazon
Merge Triplets to Form Target Triplet Medium
GoogleAmazon
Partition Labels Medium
AmazonGoogleMicrosoftMetaApple
Valid Parenthesis String Medium
AmazonGoogleMicrosoftMetaApple
Candy Hard
GoogleAmazonMicrosoftApple

Intervals

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Status Problem Difficulty Companies
Insert Interval Medium
GoogleAmazonFacebookMicrosoftBloomberg
Merge Intervals Medium
AmazonGoogleFacebookMicrosoftBloomberg
Non-overlapping Intervals Medium
GoogleAmazonFacebookMicrosoftBloomberg
Meeting Rooms Easy
GoogleAmazonFacebookMicrosoft
Meeting Rooms II Medium
GoogleAmazonFacebookMicrosoftBloomberg
Meeting Rooms III Hard
GoogleAmazonMicrosoft
Minimum Interval to Include Each Query Hard
GoogleAmazon

Math & Geometry

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Status Problem Difficulty Companies
Rotate Image Medium
AmazonGoogleFacebookMicrosoftBloomberg
Spiral Matrix Medium
MicrosoftGoogleAmazonFacebookBloomberg
Set Matrix Zeroes Medium
MicrosoftGoogleAmazonFacebookBloomberg
Reverse Integer Medium
AmazonGoogleMicrosoftApple
Integer Break Medium
GoogleAmazonMicrosoft
Excel Sheet Column Title Easy
MicrosoftAmazon
Greatest Common Divisor of Strings Easy
Amazon
Insert Greatest Common Divisors in Linked List Medium
Google
Transpose Matrix Easy
GoogleAmazon
Happy Number Easy
GoogleAmazonApple
Plus One Easy
GoogleAmazonMicrosoftApple
Roman to Integer Easy
AmazonGoogleMicrosoftApple
Pow(x, n) Medium
GoogleAmazonMicrosoftMeta
Multiply Strings Medium
GoogleAmazonMicrosoftMeta
Detect Squares Medium
GoogleAmazon
Greatest Common Divisor Traversal Hard
GoogleAmazon

Sliding Window

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Status Problem Difficulty Companies
Longest Substring Without Repeating Characters Medium
AmazonGoogleMicrosoftBloombergAdobe
Best Time to Buy and Sell Stock Easy
AmazonMetaGoogleMicrosoftBloomberg
Longest Repeating Character Replacement Medium
AmazonGoogleMicrosoftBloombergUber
Minimum Window Substring Hard
MetaAmazonGoogleMicrosoftBloomberg
Permutation in String Medium
MicrosoftGoogleAmazonApple
Contains Duplicate II Easy
GoogleAmazonMicrosoft
Minimum Size Subarray Sum Medium
GoogleAmazonMicrosoftMeta
Sliding Window Maximum Hard
GoogleAmazonMicrosoftMetaNetflix
Jump Game VII Medium
GoogleAmazon

Stack

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Status Problem Difficulty Companies
Valid Parentheses Easy
AmazonGoogleMetaMicrosoftBloomberg
Min Stack Medium
AmazonGoogleMicrosoftMetaBloomberg
Evaluate Reverse Polish Notation Medium
GoogleAmazonMicrosoftApple
Generate Parentheses Medium
GoogleAmazonMicrosoftMeta
Daily Temperatures Medium
GoogleAmazonMicrosoftMeta
Car Fleet Medium
GoogleAmazonMicrosoftUber
Sliding Window Maximum Hard
GoogleAmazonMicrosoftMetaNetflix
Baseball Game Easy
GoogleAmazonMicrosoft
Implement Stack Using Queues Easy
GoogleAmazonMicrosoft
Implement Queue using Stacks Easy
GoogleAmazonMicrosoftApple
Asteroid Collision Medium
GoogleAmazonMicrosoftMeta
Online Stock Span Medium
GoogleAmazonMicrosoftMeta
Simplify Path Medium
MetaGoogleAmazonMicrosoft
Decode String Medium
GoogleAmazonMicrosoftMetaApple
Maximum Frequency Stack Hard
GoogleAmazonMicrosoftMeta
Largest Rectangle In Histogram Hard
GoogleAmazonMicrosoftMetaApple
Valid Parenthesis String Medium
AmazonGoogleMicrosoftMetaApple

Trees

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Status Problem Difficulty Companies
Invert Binary Tree Easy
GoogleAmazonFacebookMicrosoft
Maximum Depth of Binary Tree Easy
GoogleAmazonMicrosoftFacebook
Same Tree Easy
GoogleAmazonMicrosoftFacebook
Subtree of Another Tree Easy
GoogleAmazonMicrosoftFacebook
Lowest Common Ancestor of a Binary Search Tree Easy
AmazonGoogleFacebookMicrosoftLinkedIn
Validate Binary Search Tree Medium
AmazonGoogleFacebookBloombergMicrosoft
Kth Smallest Element in a BST Medium
GoogleAmazonFacebookMicrosoft
Construct Binary Tree from Preorder and Inorder Traversal Medium
GoogleAmazonMicrosoftFacebook
Binary Tree Level Order Traversal Medium
AmazonGoogleFacebookMicrosoftBloomberg
Binary Tree Maximum Path Sum Hard
GoogleAmazonFacebookMicrosoftByteDance
Serialize and Deserialize Binary Tree Hard
GoogleAmazonFacebookMicrosoftLinkedIn
Binary Tree Inorder Traversal Easy
GoogleAmazonMicrosoft
Binary Tree Preorder Traversal Easy
GoogleAmazonMicrosoft
Binary Tree Postorder Traversal Easy
GoogleAmazonMicrosoft
Diameter of Binary Tree Easy
GoogleAmazonMicrosoftMeta
Balanced Binary Tree Easy
GoogleAmazonMicrosoftMeta
Insert into a Binary Search Tree Medium
GoogleAmazonMicrosoft
Delete Node in a BST Medium
GoogleAmazonMicrosoftMeta
Binary Tree Right Side View Medium
GoogleAmazonMicrosoftMeta
Construct Quad Tree Medium
GoogleUber
Count Good Nodes In Binary Tree Medium
GoogleAmazonMicrosoftMeta
House Robber III Medium
GoogleAmazonMicrosoftMetaApple
Delete Leaves With a Given Value Medium
GoogleAmazonMicrosoft

Tries

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Status Problem Difficulty Companies
Implement Trie (Prefix Tree) Medium
GoogleAmazonMicrosoftFacebook
Design Add and Search Words Data Structure Medium
AmazonGoogleFacebookMicrosoft
Word Search II Hard
GoogleAmazonMicrosoftUberApple
Extra Characters in a String Medium
GoogleAmazon

Two Pointers

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Status Problem Difficulty Companies
Valid Palindrome Easy
MetaMicrosoftGoogleAmazonApple
3Sum Medium
AmazonMetaGoogleMicrosoftAdobe
Container With Most Water Medium
AmazonGoogleMetaMicrosoftBloomberg
Reverse String Easy
MicrosoftAppleAmazonGoogle
Valid Palindrome II Easy
MetaGoogleAmazonMicrosoft
Merge Strings Alternately Easy
GoogleAmazonMicrosoft
Merge Sorted Array Easy
MetaGoogleAmazonMicrosoft
Remove Duplicates From Sorted Array Easy
MetaGoogleAmazonMicrosoft
Two Sum II - Input Array Is Sorted Medium
AmazonGoogleMicrosoftAdobe
4Sum Medium
GoogleAmazonMicrosoft
Rotate Array Medium
MicrosoftGoogleAmazonApple
Boats to Save People Medium
GoogleAmazonMicrosoft
Trapping Rain Water Hard
GoogleAmazonMicrosoftMetaApple
Find K Closest Elements Medium
GoogleAmazonMicrosoftMeta
Find The Duplicate Number Medium
GoogleAmazonMicrosoftMeta
Longest Turbulent Subarray Medium
GoogleAmazon
Partition Labels Medium
AmazonGoogleMicrosoftMetaApple

Linked List

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Status Problem Difficulty Companies
Reverse Linked List Easy
AmazonGoogleMetaMicrosoftApple
Merge Two Sorted Lists Easy
AmazonMicrosoftGoogleMetaBloomberg
Reorder List Medium
AmazonGoogleMetaMicrosoft
Remove Nth Node From End of List Medium
AmazonGoogleMetaMicrosoftApple
Merge K Sorted Lists Hard
AmazonGoogleMetaMicrosoftBloomberg
Linked List Cycle Easy
AmazonMicrosoftGoogleMeta
Copy List With Random Pointer Medium
MetaGoogleAmazonMicrosoft
Add Two Numbers Medium
AmazonGoogleMicrosoftMetaApple
Find The Duplicate Number Medium
GoogleAmazonMicrosoftMeta
Reverse Linked List II Medium
GoogleAmazonMicrosoftMeta
Design Circular Queue Medium
GoogleAmazonMicrosoft
LRU Cache Medium
GoogleAmazonMicrosoftMetaApple
LFU Cache Hard
GoogleAmazonMicrosoftMetaApple
Reverse Nodes In K Group Hard
GoogleAmazonMicrosoftMetaApple
Insert Greatest Common Divisors in Linked List Medium
Google