Retag most popular Leetcode problems

leetcode_retag.md

• Pre Sum (hash map)

  • 1. Two Sum
  • 15. 3Sum
  • 18. 4Sum
  • 410. Split Array Largest Sum
  • 560. Subarray Sum Equals K

• Calculation

  • 2. Add Two Numbers
  • 13. Roman to Integer
  • 31. Next Permutation
  • 134. Gas Station
  • 166. Fraction to Recurring Decimal
  • 202. Happy Number
  • 238. Product of Array Except Self
  • 273. Integer to English Words
  • 334. Increasing Triplet Subsequence
  • 621. Task Scheduler

• Monotonous Stack

  • 42. Trapping Rain Water
  • 84. Largest Rectangle in Histogram
  • 85. Maximal Rectangle
  • 456. 132 Pattern
  • 735. Asteroid Collision
  • 739. Daily Temperatures

• Decode Stack / DFS

  • 341. Flatten Nested List Iterator
  • 394. Decode String
  • 726. Number of Atoms
  • 1087. Brace Expansion

• Sort First

  • 16. 3Sum Closest
  • 56. Merge Intervals
  • 57. Insert Interval
  • 253. Meeting Rooms II

• Matrix Loop

  • 48. Rotate Image
  • 54. Spiral Matrix
  • 59. Spiral Matrix II
  • 498. Diagonal Traverse

• Trie Tree

  • 208. Implement Trie (Prefix Tree)
  • 211. Add and Search Word - Data structure design

• Data Structure Design

  • 146. LRU Cache
  • 155. Min Stack
  • 158. Read N Characters Given Read4 II - Call multiple times
  • 173. Binary Search Tree Iterator
  • 297. Serialize and Deserialize Binary Tree
  • 449. Serialize and Deserialize BST
  • 981. Time Based Key-Value Store

• Hash map compare

  • 49. Group Anagrams

• Palindromic Substring

  • 5. Longest Palindromic Substring

• Merge Sort

  • 4. Median of Two Sorted Arrays
  • 21. Merge Two Sorted Lists
  • 23. Merge k Sorted Lists
  • 88. Merge Sorted Array
  • 148. Sort List

• Merge Combine Sort

  • 315. Count of Smaller Numbers After Self

• Two Pointer Slide window

  • 3. Longest Substring Without Repeating Characters
  • 76. Minimum Window Substring
  • 159. Longest Substring with At Most Two Distinct Characters
  • 209. Minimum Size Subarray Sum
  • 340. Longest Substring with At Most K Distinct Characters
  • 438. Find All Anagrams in a String
  • 567. Permutation in String
  • 727. Minimum Window Subsequence

• Two Pointer

  • 11. Container With Most Water

• Heap (K elements)

  • 215. Kth Largest Element in an Array
  • 239. Sliding Window Maximum
  • 347. Top K Frequent Elements
  • 787. Cheapest Flights Within K Stops
  • 973. K Closest Points to Origin

• Multiple Heap

  • 295. Find Median from Data Stream

• Basic DFS

  • 17. Letter Combinations of a Phone Number
  • 22. Generate Parentheses
  • 37. Sudoku Solver
  • 39. Combination Sum
  • 46. Permutations
  • 78. Subsets
  • 79. Word Search
  • 200. Number of Islands
  • 210. Course Schedule II
  • 212. Word Search II
  • 282. Expression Add Operators
  • 322. Coin Change
  • 403. Frog Jump

• DFS Hard

  • 51. N-Queens
  • 140. Word Break II
  • 489. Robot Room Cleaner

• Basic BFS

  • 64. Minimum Path Sum
  • 126. Word Ladder II
  • 207. Course Schedule
  • 863. All Nodes Distance K in Binary Tree

• Topological Sort

  • 207. Course Schedule
  • 210. Course Schedule II
  • 269. Alien Dictionary

• Basic Binary Search

  • 33. Search in Rotated Sorted Array
  • 34. Find First and Last Position of Element in Sorted Array
  • 81. Search in Rotated Sorted Array II
  • 153. Find Minimum in Rotated Sorted Array
  • 154. Find Minimum in Rotated Sorted Array II
  • 162. Find Peak Element
  • 240. Search a 2D Matrix II

• Binary Search Hard

  • 214. Shortest Palindrome
  • 287. Find the Duplicate Number
  • 528. Random Pick with Weight
  • 647. Palindromic Substrings
  • 1055. Shortest Way to Form String

• DP Stock

  • 121. Best Time to Buy and Sell Stock
  • 122. Best Time to Buy and Sell Stock II
  • 123. Best Time to Buy and Sell Stock III
  • 188. Best Time to Buy and Sell Stock IV

• Basic DP

  • 10. Regular Expression Matching
  • 36. Valid Sudoku
  • 44. Wildcard Matching
  • 45. Jump Game II
  • 62. Unique Paths
  • 70. Climbing Stairs
  • 91. Decode Ways
  • 96. Unique Binary Search Trees
  • 97. Interleaving String
  • 128. Longest Consecutive Sequence
  • 152. Maximum Product Subarray
  • 139. Word Break
  • 198. House Robber
  • 221. Maximal Square
  • 256. Paint House
  • 300. Longest Increasing Subsequence

• Swap Trick

  • 41. First Missing Positive
  • 75. Sort Colors
  • 283. Move Zeroes

• Random

  • 528. Random Pick with Weight

• Stack Basic

  • 7. Reverse Integer
  • 20. Valid Parentheses
  • 150. Evaluate Reverse Polish Notation
  • 224. Basic Calculator
  • 227. Basic Calculator II
  • 772. Basic Calculator III

• Bruce Force

  • 1007. Minimum Domino Rotations For Equal Row

• Serialize and Deserialize

  • 297. Serialize and Deserialize Binary Tree

• Tree Recursion

  • 124. Binary Tree Maximum Path Sum
  • 236. Lowest Common Ancestor of a Binary Tree
  • 543. Diameter of Binary Tree
  • 834. Sum of Distances in Tree

• Tree Non Recursion

  • 116. Populating Next Right Pointers in Each Node
  • 117. Populating Next Right Pointers in Each Node II
  • 199. Binary Tree Right Side View

• Validate Tree

  • 98. Validate Binary Search Tree

• Construct or recover Tree

  • 99. Recover Binary Search Tree
  • 105. Construct Binary Tree from Preorder and Inorder Traversal
  • 109. Convert Sorted List to Binary Search Tree

• Clone

  • 138. Copy List with Random Pointer
  • 133. Clone Graph