Arrays & Strings

• Two Sum
• Best Time to Buy and Sell Stock
• Maximum Subarray
• Product of Array Except Self
• Set Matrix Zeroes
• Rotate Image
• Longest Substring Without Repeating Characters
• Longest Palindromic Substring
• Container With Most Water
• 3Sum
• Group Anagrams
• Longest Common Prefix
• Valid Anagram
• Minimum Window Substring
• Sliding Window Maximum
• Find All Anagrams in a String
• String to Integer
• Integer to Roman
• Roman to Integer
• Zigzag Conversion
• Generate Parentheses
• Multiply Strings
• Valid Palindrome
• Reverse Words in a String
• Word Break

Searching & Sorting

• Binary Search
• Search in Rotated Sorted Array
• Find First and Last Position
• Median of Two Sorted Arrays
• Merge Intervals
• Meeting Rooms
• Insert Interval
• Sort Colors
• Find Peak Element
• Kth Largest Element in an Array
• Top K Frequent Elements
• Merge Sorted Array
• H-Index
• Search a 2D Matrix
• Find Minimum in Rotated Sorted Array
• Search a 2D Matrix II
• First Missing Positive
• Largest Number
• Wiggle Sort II
• Russian Doll Envelopes

Linked List

• Reverse Linked List
• Merge Two Sorted Lists
• Detect Cycle in Linked List
• Add Two Numbers
• LRU Cache
• Remove Nth Node From End of List
• Palindrome Linked List
• Intersection of Two Linked Lists
• Copy List with Random Pointer
• Rotate List
• Flatten a Multilevel Doubly Linked List
• Partition List
• Reorder List
• Sort List
• Reverse Nodes in k-Group
• Swap Nodes in Pairs

Stacks & Queues

• Valid Parentheses
• Min Stack
• Implement Queue using Stacks
• Daily Temperatures
• Evaluate Reverse Polish Notation
• Largest Rectangle in Histogram
• Sliding Window Maximum
• Decode String
• Remove K Digits
• Simplify Path
• Basic Calculator
• Asteroid Collision
• Next Greater Element
• Monotonic Stack Problems

Recursion & Backtracking

• Subsets
• Combination Sum
• Word Search
• N-Queens
• Sudoku Solver
• Letter Combinations of a Phone Number
• Permutations
• Combinations
• Generate Parentheses
• Palindrome Partitioning
• Restore IP Addresses
• Word Ladder
• Word Ladder II

Trees & Graphs

• Maximum Depth of Binary Tree
• Validate Binary Search Tree
• Binary Tree Level Order Traversal
• Lowest Common Ancestor
• Number of Islands
• Clone Graph
• Course Schedule
• Course Schedule II
• Word Ladder
• Surrounded Regions
• Rotting Oranges
• Pacific Atlantic Water Flow
• Accounts Merge
• Binary Tree Inorder Traversal
• Binary Tree Preorder Traversal
• Binary Tree Postorder Traversal
• Construct Binary Tree from Preorder and Inorder
• Serialize and Deserialize Binary Tree
• Binary Tree Maximum Path Sum
• Path Sum
• Path Sum II

Dynamic Programming

• Climbing Stairs
• House Robber
• House Robber II
• Coin Change
• Longest Increasing Subsequence
• Word Break
• Edit Distance
• Unique Paths
• Unique Paths II
• Minimum Path Sum
• Maximal Square
• Longest Palindromic Subsequence
• Regular Expression Matching
• Wildcard Matching
• Interleaving String
• Burst Balloons
• Palindrome Partitioning II
• Scramble String
• Longest Valid Parentheses

Advanced/Hard

• Trapping Rain Water
• Sliding Window Maximum
• Median Sliding Window
• LFU Cache
• Minimum Window Substring
• Shortest Palindrome
• Word Ladder II
• Alien Dictionary
• Largest Rectangle in Histogram
• Maximal Rectangle
• Candy
• First Missing Positive
• Sudoku Solver
• Strongly Connected Components
• Critical Connections in a Network
• Word Search II
• Regex Matching
• Wildcard Matching