Topic Tags¶

Array¶

• 1. Two Sum
• 11. Container With Most Water
• 15. 3Sum
• 209. Minimum Size Subarray Sum
• 27. Remove Element
• 349. Intersection of Two Arrays
• 454. 4Sum II
• 54. Spiral Matrix
• 59. Spiral Matrix II
• 704. Binary Search
• 977. Squares of a Sorted Array

Binary Search¶

• 209. Minimum Size Subarray Sum
• 349. Intersection of Two Arrays
• 704. Binary Search

Binary Tree¶

• 144. Binary Tree Preorder Traversal
• 145. Binary Tree Postorder Traversal
• 94. Binary Tree Inorder Traversal

Bit Manipulation¶

• 1009. Complement of Base 10 Integer
• 461. Hamming Distance
• 476. Number Complement
• 67. Add Binary

Counting¶

• 383. Ransom Note

Depth-First Search¶

• 144. Binary Tree Preorder Traversal
• 145. Binary Tree Postorder Traversal
• 94. Binary Tree Inorder Traversal

Design¶

• 707. Design Linked List

Greedy¶

• 11. Container With Most Water

Hash Table¶

• 1. Two Sum
• 142. Linked List Cycle II
• 160. Intersection of Two Linked Lists
• 202. Happy Number
• 242. Valid Anagram
• 349. Intersection of Two Arrays
• 383. Ransom Note
• 454. 4Sum II

Linked List¶

• 142. Linked List Cycle II
• 160. Intersection of Two Linked Lists
• 19. Remove Nth Node From End of List
• 2. Add Two Numbers
• 203. Remove Linked List Elements
• 206. Reverse Linked List
• 707. Design Linked List
• 92. Reverse Linked List II

Math¶

• 2. Add Two Numbers
• 202. Happy Number
• 67. Add Binary
• 7. Reverse Integer
• 9. Palindrome Number

Matrix¶

• 54. Spiral Matrix
• 59. Spiral Matrix II

Prefix Sum¶

• 209. Minimum Size Subarray Sum

Recursion¶

• 2. Add Two Numbers
• 203. Remove Linked List Elements
• 206. Reverse Linked List

Simulation¶

• 54. Spiral Matrix
• 59. Spiral Matrix II
• 67. Add Binary

Sliding Window¶

• 209. Minimum Size Subarray Sum

Sorting¶

• 15. 3Sum
• 242. Valid Anagram
• 349. Intersection of Two Arrays
• 977. Squares of a Sorted Array

Stack¶

• 144. Binary Tree Preorder Traversal
• 145. Binary Tree Postorder Traversal
• 20. Valid Parentheses
• 94. Binary Tree Inorder Traversal

String¶

• 14. Longest Common Prefix
• 165. Compare Version Numbers
• 20. Valid Parentheses
• 242. Valid Anagram
• 383. Ransom Note
• 482. License Key Formatting
• 557. Reverse Words in a String III
• 67. Add Binary

Tree¶

• 144. Binary Tree Preorder Traversal
• 145. Binary Tree Postorder Traversal
• 94. Binary Tree Inorder Traversal

Trie¶

• 14. Longest Common Prefix

Two Pointers¶

• 11. Container With Most Water
• 142. Linked List Cycle II
• 15. 3Sum
• 160. Intersection of Two Linked Lists
• 165. Compare Version Numbers
• 19. Remove Nth Node From End of List
• 202. Happy Number
• 27. Remove Element
• 349. Intersection of Two Arrays
• 557. Reverse Words in a String III
• 977. Squares of a Sorted Array