Showing 50 problems
#1
Two Sum
EasyArrayHash Map
#3
Longest Substring Without Repeating Characters
MediumStringSliding WindowHash Map
#5
Longest Palindromic Substring
MediumStringDP
#11
Container With Most Water
MediumArrayTwo PointersGreedy
#15
3Sum
MediumArrayTwo PointersSorting
#19
Remove Nth Node From End of List
MediumLinked ListTwo Pointers
#20
Valid Parentheses
EasyStringStack
#21
Merge Two Sorted Lists
EasyLinked ListRecursion
#23
Merge k Sorted Lists
HardLinked ListDivide and ConquerHeap
#33
Search in Rotated Sorted Array
MediumArrayBinary Search
#36
Valid Sudoku
MediumArrayHash SetMatrix
#39
Combination Sum
MediumArrayBacktracking
#49
Group Anagrams
MediumArrayHash MapStringSorting
#53
Maximum Subarray
MediumArrayDPDivide and Conquer
#62
Unique Paths
MediumMathDPCombinatorics
#70
Climbing Stairs
EasyMathDPMemoization
#79
Word Search
MediumArrayBacktrackingMatrix
#91
Decode Ways
MediumStringDP
#94
Binary Tree Inorder Traversal
EasyTreeDFSStackBinary Tree
#98
Validate Binary Search Tree
MediumTreeDFSBinary Search TreeBinary Tree
#100
Same Tree
EasyTreeDFSBFSBinary Tree
#102
Binary Tree Level Order Traversal
MediumTreeBFSBinary Tree
#104
Maximum Depth of Binary Tree
EasyTreeDFSBFSBinary Tree
#121
Best Time to Buy and Sell Stock
EasyArrayDP
#125
Valid Palindrome
EasyTwo PointersString
#128
Longest Consecutive Sequence
MediumArrayHash SetUnion Find
#133
Clone Graph
MediumHash MapDFSBFSGraph
#139
Word Break
MediumArrayHash SetStringDPTrieMemoization
#141
Linked List Cycle
EasyHash TableLinked ListTwo Pointers
#143
Reorder List
MediumLinked ListTwo PointersStackRecursion
#153
Find Minimum in Rotated Sorted Array
MediumArrayBinary Search
#155
Min Stack
MediumStackDesign
#167
Two Sum II - Input Array Is Sorted
MediumArrayTwo PointersBinary Search
#198
House Robber
MediumArrayDP
#200
Number of Islands
MediumArrayDFSBFSUnion FindMatrix
#206
Reverse Linked List
EasyLinked ListRecursion
#207
Course Schedule
MediumDFSBFSGraphTopological Sort
#213
House Robber II
MediumArrayDP
#217
Contains Duplicate
EasyArrayHash SetSorting
#226
Invert Binary Tree
EasyTreeDFSBFSBinary Tree
#232
Implement Queue using Stacks
EasyStackDesignQueue
#235
Lowest Common Ancestor of a Binary Search Tree
MediumTreeDFSBinary Search TreeBinary Tree
#238
Product of Array Except Self
MediumArrayPrefix Sum
#242
Valid Anagram
EasyHash MapStringSorting
#271
Encode and Decode Strings
MediumArrayStringDesign
#300
Longest Increasing Subsequence
MediumArrayBinary SearchDP
#322
Coin Change
MediumArrayDPBFS
#347
Top K Frequent Elements
MediumArrayHash MapSortingHeapBucket Sort
#417
Pacific Atlantic Water Flow
MediumArrayDFSBFSMatrix
#647
Palindromic Substrings
MediumStringDP