Top 150
Amazon
Easy
Medium
Hard
completed: 0
todo: 150
Array / String
Merge Sorted Array
Easy
Remove Element
Easy
Remove Duplicates from Sorted Array
Easy
Remove Duplicates from Sorted Array II
Medium
Majority Element
Easy
Rotate Array
Medium
Best Time to Buy and Sell Stock
Easy
Best Time to Buy and Sell Stock II
Medium
Jump Game
Medium
Jump Game II
Medium
H-Index
Medium
Insert Delete GetRandom O(1)
Medium
Product of Array Except Self
Medium
Gas Station
Medium
Candy
Hard
Trapping Rain Water
Hard
Roman to Integer
Easy
Integer to Roman
Medium
Length of Last Word
Easy
Longest Common Prefix
Easy
Reverse Words in a String
Medium
Zigzag Conversion
Medium
Find the Index of the First Occurrence in a String
Easy
Text Justification
Hard
Two Pointers
Valid Palindrome
Easy
Is Subsequence
Easy
Two Sum II - Input Array Is Sorted
Medium
Container With Most Water
Medium
3Sum
Medium
Sliding Window
Minimum Size Subarray Sum
Medium
Longest Substring Without Repeating Characters
Medium
Substring with Concatenation of All Words
Hard
Minimum Window Substring
Hard
Matrix
Valid Sudoku
Medium
Spiral Matrix
Medium
Rotate Image
Medium
Set Matrix Zeroes
Medium
Game of Life
Medium
Hashmap
Ransom Note
Easy
Isomorphic Strings
Easy
Word Pattern
Easy
Valid Anagram
Easy
Group Anagrams
Medium
Two Sum
Easy
Happy Number
Easy
Contains Duplicate II
Easy
Longest Consecutive Sequence
Medium
Intervals
Summary Ranges
Easy
Merge Intervals
Medium
Insert Interval
Medium
Minimum Number of Arrows to Burst Balloons
Medium
Stack
Valid Parentheses
Easy
Simplify Path
Medium
Min Stack
Medium
Evaluate Reverse Polish Notation
Medium
Basic Calculator
Hard
Linked List
Linked List Cycle
Easy
Add Two Numbers
Medium
Merge Two Sorted Lists
Easy
Copy List with Random Pointer
Medium
Reverse Linked List II
Medium
Reverse Nodes in k-Group
Hard
Remove Nth Node From End of List
Medium
Remove Duplicates from Sorted List II
Medium
Rotate List
Medium
Partition List
Medium
LRU Cache
Medium
Binary Tree General
Maximum Depth of Binary Tree
Easy
Same Tree
Easy
Invert Binary Tree
Easy
Symmetric Tree
Easy
Construct Binary Tree from Preorder and Inorder Traversal
Medium
Construct Binary Tree from Inorder and Postorder Traversal
Medium
Populating Next Right Pointers in Each Node II
Medium
Flatten Binary Tree to Linked List
Medium
Path Sum
Easy
Sum Root to Leaf Numbers
Medium
Binary Tree Maximum Path Sum
Hard
Binary Search Tree Iterator
Medium
Count Complete Tree Nodes
Easy
Lowest Common Ancestor of a Binary Tree
Medium
Binary Tree BFS
Binary Tree Right Side View
Medium
Average of Levels in Binary Tree
Easy
Binary Tree Level Order Traversal
Medium
Binary Tree Zigzag Level Order Traversal
Medium
Binary Search Tree
Minimum Absolute Difference in BST
Easy
Kth Smallest Element in a BST
Medium
Validate Binary Search Tree
Medium
Graph General
Number of Islands
Medium
Surrounded Regions
Medium
Clone Graph
Medium
Evaluate Division
Medium
Course Schedule
Medium
Course Schedule II
Medium
Graph BFS
Snakes and Ladders
Medium
Minimum Genetic Mutation
Medium
Word Ladder
Hard
Trie
Implement Trie (Prefix Tree)
Medium
Design Add and Search Words Data Structure
Medium
Word Search II
Hard
Backtracking
Letter Combinations of a Phone Number
Medium
Combinations
Medium
Permutations
Medium
Combination Sum
Medium
N-Queens II
Hard
Generate Parentheses
Medium
Word Search
Medium
Divide & Conquer
Convert Sorted Array to Binary Search Tree
Easy
Sort List
Medium
Construct Quad Tree
Medium
Merge k Sorted Lists
Hard
Kadane's Algorithm
Maximum Subarray
Medium
Maximum Sum Circular Subarray
Medium
Binary Search
Search Insert Position
Easy
Search a 2D Matrix
Medium
Find Peak Element
Medium
Search in Rotated Sorted Array
Medium
Find First and Last Position of Element in Sorted Array
Medium
Find Minimum in Rotated Sorted Array
Medium
Median of Two Sorted Arrays
Hard
Heap
Kth Largest Element in an Array
Medium
IPO
Hard
Find K Pairs with Smallest Sums
Medium
Find Median from Data Stream
Hard
Bit Manipulation
Add Binary
Easy
Reverse Bits
Easy
Number of 1 Bits
Easy
Single Number
Easy
Single Number II
Medium
Bitwise AND of Numbers Range
Medium
Math
Palindrome Number
Easy
Plus One
Easy
Factorial Trailing Zeroes
Medium
Sqrt(x)
Easy
Pow(x, n)
Medium
Max Points on a Line
Hard
1D DP
Climbing Stairs
Easy
House Robber
Medium
Word Break
Medium
Coin Change
Medium
Longest Increasing Subsequence
Medium
Multidimensional DP
Triangle
Medium
Minimum Path Sum
Medium
Unique Paths II
Medium
Longest Palindromic Substring
Medium
Interleaving String
Medium
Edit Distance
Medium
Best Time to Buy and Sell Stock III
Hard
Best Time to Buy and Sell Stock IV
Hard
Maximal Square
Medium