Questions
155 of 155 questions
Two Sum#1
EasyArrays & Hashing
AmazonGoogleMeta
Contains Duplicate#217
EasyArrays & Hashing
AmazonAppleGoogle
Valid Anagram#242
EasyArrays & Hashing
AmazonGoogleMeta
Group Anagrams#49
MediumArrays & Hashing
AmazonMetaGoogle
Product of Array Except Self#238
MediumArrays & Hashing
AmazonMetaGoogle
Longest Consecutive Sequence#128
MediumArrays & Hashing
MetaAmazonGoogle
Valid Sudoku#36
MediumArrays & Hashing
Longest Common Prefix#14
EasyArrays & Hashing
Majority Element#169
EasyArrays & Hashing
Insert Delete GetRandom O(1)#380
MediumArrays & Hashing
Maximum Average Subarray I#643
EasySliding Window
AmazonGoogle
Minimum Size Subarray Sum#209
MediumSliding Window
AmazonGoogleMeta
Longest Substring Without Repeating Characters#3
MediumSliding Window
AmazonGoogleMeta
Longest Repeating Character Replacement#424
MediumSliding Window
GoogleAmazonBloomberg
Permutation in String#567
MediumSliding Window
AmazonGoogleMeta
Minimum Window Substring#76
HardSliding Window
AmazonGoogleMeta
Sliding Window Maximum#239
HardSliding Window
AmazonGoogleMeta
Valid Palindrome#125
EasyTwo Pointers
AmazonMicrosoftGoogle
Two Sum II - Input Array Is Sorted#167
MediumTwo Pointers
AmazonGoogleApple
Remove Duplicates from Sorted Array#26
EasyTwo Pointers
AmazonMicrosoftGoogle
3Sum#15
MediumTwo Pointers
AmazonGoogleMeta
Container With Most Water#11
MediumTwo Pointers
AmazonGoogleMeta
Trapping Rain Water#42
HardTwo Pointers
AmazonGoogleMeta
Sort Colors#75
MediumTwo Pointers
MetaMicrosoftGoogle
Is Subsequence#392
EasyTwo Pointers
Happy Number#202
EasyFast & Slow Pointers
AmazonGoogleLinkedIn
Linked List Cycle#141
EasyFast & Slow Pointers
AmazonGoogleMicrosoft
Find the Duplicate Number#287
MediumFast & Slow Pointers
AmazonGoogleMeta
Middle of the Linked List#876
EasyFast & Slow Pointers
AmazonGoogleMicrosoft
Merge Intervals#56
MediumMerge Intervals
AmazonGoogleMeta
Insert Interval#57
MediumMerge Intervals
AmazonGoogleMeta
Meeting Rooms#252
EasyMerge Intervals
AmazonGoogleMeta
Meeting Rooms II#253
MediumMerge Intervals
AmazonGoogleMeta
Non-overlapping Intervals#435
MediumMerge Intervals
GoogleAmazonMeta
Missing Number#268
EasyCyclic Sort
AmazonGoogleMicrosoft
Find All Numbers Disappeared in an Array#448
EasyCyclic Sort
AmazonGoogle
Find the Duplicate Number (Cyclic Sort approach)#287
MediumCyclic Sort
AmazonGoogleMeta
First Missing Positive#41
HardCyclic Sort
AmazonGoogleMeta
Reverse Linked List#206
EasyIn-place List Reversal
AmazonGoogleMeta
Reverse Linked List II#92
MediumIn-place List Reversal
MetaAmazonMicrosoft
Reverse Nodes in k-Group#25
HardIn-place List Reversal
GoogleAmazonMeta
Rotate List#61
MediumIn-place List Reversal
AmazonGoogleMicrosoft
Binary Tree Level Order Traversal#102
MediumTree BFS
AmazonGoogleMeta
Binary Tree Right Side View#199
MediumTree BFS
AmazonGoogleMeta
Average of Levels in Binary Tree#637
EasyTree BFS
AmazonGoogle
Minimum Depth of Binary Tree#111
EasyTree BFS
AmazonGoogleMicrosoft
Binary Tree Zigzag Level Order Traversal#103
MediumTree BFS
AmazonGoogleMeta
Path Sum#112
EasyTree DFS
AmazonGoogleMicrosoft
Path Sum II#113
MediumTree DFS
AmazonGoogleMeta
Maximum Depth of Binary Tree#104
EasyTree DFS
AmazonGoogleLinkedIn
Diameter of Binary Tree#543
EasyTree DFS
AmazonGoogleMeta
Validate Binary Search Tree#98
MediumTree DFS
AmazonGoogleMeta
Binary Tree Maximum Path Sum#124
HardTree DFS
AmazonGoogleMeta
Lowest Common Ancestor of BST#235
MediumTree DFS
AmazonMetaMicrosoft
Lowest Common Ancestor of Binary Tree#236
MediumTree DFS
MetaAmazonGoogle
Kth Smallest Element in a BST#230
MediumTree DFS
AmazonBloombergGoogle
Serialize and Deserialize Binary Tree#297
HardTree DFS
MetaGoogleAmazon
Recover Binary Search Tree#99
HardTree DFS
AmazonGoogleMicrosoft
Kth Largest Element in a Stream#703
EasyTwo Heaps
AmazonGoogleMeta
Find Median from Data Stream#295
HardTwo Heaps
AmazonGoogleMeta
Sliding Window Median#480
HardTwo Heaps
AmazonGoogle
Subsets#78
MediumSubsets / Combinations
AmazonGoogleMeta
Subsets II#90
MediumSubsets / Combinations
AmazonGoogleMeta
Permutations#46
MediumSubsets / Combinations
AmazonGoogleMeta
Combinations#77
MediumSubsets / Combinations
AmazonGoogleMeta
Letter Combinations of a Phone Number#17
MediumSubsets / Combinations
AmazonGoogleMeta
Binary Search#704
EasyModified Binary Search
AmazonGoogleMicrosoft
Search in Rotated Sorted Array#33
MediumModified Binary Search
AmazonGoogleMeta
Find Minimum in Rotated Sorted Array#153
MediumModified Binary Search
AmazonGoogleMeta
Koko Eating Bananas#875
MediumModified Binary Search
AmazonGoogleMeta
Median of Two Sorted Arrays#4
HardModified Binary Search
AmazonGoogleMeta
Search a 2D Matrix#74
MediumModified Binary Search
AmazonGoogleMicrosoft
Find Peak Element#162
MediumModified Binary Search
GoogleMetaMicrosoft
Split Array Largest Sum#410
HardModified Binary Search
GoogleMetaAmazon
Kth Smallest Element in a Sorted Matrix#378
MediumModified Binary Search
GoogleAmazonApple
Next Greater Element I#496
EasyMonotonic Stack
AmazonGoogleMeta
Daily Temperatures#739
MediumMonotonic Stack
AmazonGoogleMeta
Online Stock Span#901
MediumMonotonic Stack
AmazonGoogleBloomberg
Largest Rectangle in Histogram#84
HardMonotonic Stack
GoogleAmazonMeta
Trapping Rain Water (Stack)#42
HardMonotonic Stack
AmazonGoogleMeta
Maximal Rectangle#85
HardMonotonic Stack
AmazonGoogleMeta
Sum of Subarray Minimums#907
HardMonotonic Stack
AmazonGoogleBloomberg
Car Fleet#853
MediumMonotonic Stack
Combination Sum#39
MediumBacktracking
AmazonGoogleMeta
Word Search#79
MediumBacktracking
AmazonGoogleMeta
N-Queens#51
HardBacktracking
AmazonGoogleMeta
Sudoku Solver#37
HardBacktracking
AmazonGoogleMeta
Generate Parentheses#22
MediumBacktracking
GoogleAmazonMeta
Palindrome Partitioning#131
MediumBacktracking
AmazonGoogleMeta
Implement Trie (Prefix Tree)#208
MediumTrie
AmazonGoogleMeta
Design Add and Search Words Data Structure#211
MediumTrie
AmazonGoogleMeta
Replace Words#648
MediumTrie
AmazonGoogle
Palindrome Pairs#336
HardTrie
GoogleAmazonBloomberg
Word Search II#212
HardTrie
AmazonGoogleMeta
Course Schedule#207
MediumTopological Sort
AmazonGoogleMeta
Course Schedule II#210
MediumTopological Sort
AmazonGoogleMeta
Minimum Height Trees#310
MediumTopological Sort
GoogleAmazon
Alien Dictionary#269
HardTopological Sort
AmazonGoogleMeta
Number of Islands#200
MediumGraph BFS / DFS
AmazonGoogleMeta
Clone Graph#133
MediumGraph BFS / DFS
AmazonGoogleMeta
Pacific Atlantic Water Flow#417
MediumGraph BFS / DFS
AmazonGoogleMeta
Rotting Oranges#994
MediumGraph BFS / DFS
AmazonGoogleMeta
Walls and Gates#286
MediumGraph BFS / DFS
AmazonGoogleMeta
Redundant Connection#684
MediumGraph BFS / DFS
AmazonGoogleLinkedIn
Word Ladder#127
HardGraph BFS / DFS
AmazonGoogleMeta
Accounts Merge#721
MediumGraph BFS / DFS
GoogleAmazonMeta
Critical Connections in a Network#1192
HardGraph BFS / DFS
AmazonGoogleMeta
Reconstruct Itinerary#332
HardGraph BFS / DFS
GoogleAmazonMeta
Swim in Rising Water#778
HardGraph BFS / DFS
GoogleAmazon
Number of Connected Components in Undirected Graph#323
MediumGraph BFS / DFS
LinkedInGoogleAmazon
Surrounded Regions#130
MediumGraph BFS / DFS
Climbing Stairs#70
EasyDynamic Programming
AmazonGoogleBloomberg
House Robber#198
MediumDynamic Programming
AmazonGoogleMeta
Partition Equal Subset Sum#416
MediumDynamic Programming
AmazonGoogleMeta
Coin Change#322
MediumDynamic Programming
AmazonGoogleMeta
Longest Common Subsequence#1143
MediumDynamic Programming
AmazonGoogleMeta
Word Break#139
MediumDynamic Programming
AmazonGoogleMeta
Unique Paths#62
MediumDynamic Programming
AmazonGoogleMeta
Maximum Subarray#53
MediumDynamic Programming
AmazonGoogleLinkedIn
Edit Distance#72
HardDynamic Programming
AmazonGoogleMeta
Maximum Product Subarray#152
MediumDynamic Programming
AmazonLinkedInGoogle
Burst Balloons#312
HardDynamic Programming
AmazonGoogle
Jump Game#55
MediumDynamic Programming
AmazonGoogleMeta
Distinct Subsequences#115
HardDynamic Programming
AmazonGoogleBloomberg
Jump Game II#45
MediumDynamic Programming
AmazonGoogleMeta
Wildcard Matching#44
HardDynamic Programming
AmazonGoogleMeta
Decode Ways#91
MediumDynamic Programming
MetaAmazonGoogle
Interleaving String#97
HardDynamic Programming
GoogleAmazonBloomberg
Longest Palindromic Substring#5
MediumDynamic Programming
AmazonGoogleMicrosoft
Longest Increasing Subsequence#300
MediumDynamic Programming
AmazonGoogleMeta
Palindromic Substrings#647
MediumDynamic Programming
MetaMicrosoftAmazon
Russian Doll Envelopes#354
HardDynamic Programming
GoogleAmazonBloomberg
Regular Expression Matching#10
HardDynamic Programming
MetaGoogleBloomberg
Coin Change II#518
MediumDynamic Programming
AmazonGoogleMeta
Target Sum#494
MediumDynamic Programming
AmazonGoogleMeta
Single Number#136
EasyBitwise XOR
AmazonGoogleMicrosoft
Single Number III#260
MediumBitwise XOR
AmazonGoogle
Missing Number (XOR approach)#268
EasyBitwise XOR
AmazonGoogleMicrosoft
Kth Largest Element in an Array#215
MediumHeap / Priority Queue
MetaAmazonGoogle
Top K Frequent Elements#347
MediumHeap / Priority Queue
AmazonMetaGoogle
K Closest Points to Origin#973
MediumHeap / Priority Queue
AmazonMetaGoogle
Task Scheduler#621
MediumHeap / Priority Queue
MetaAmazonGoogle
Reorganize String#767
MediumHeap / Priority Queue
GoogleAmazonMeta
Merge k Sorted Lists#23
HardHeap / Priority Queue
AmazonMetaGoogle
LRU Cache#146
MediumHeap / Priority Queue
AmazonGoogleMeta
Find Median from Data Stream#295
HardHeap / Priority Queue
AmazonGoogleMeta
IPO#502
HardHeap / Priority Queue
AmazonGoogleBloomberg
Smallest Range Covering Elements from K Lists#632
HardHeap / Priority Queue
GoogleAmazonBloomberg
LFU Cache#460
HardHeap / Priority Queue
Valid Parentheses#20
EasyStack
Min Stack#155
MediumStack
Evaluate Reverse Polish Notation#150
MediumStack
Nim Game#292
EasyGame Theory & Minimax
Predict the Winner#486
MediumGame Theory & Minimax
Stone Game#877
MediumGame Theory & Minimax