# Problem Difficulty Type 10 Regular Expression Matching Hard dp 32 Longest Valid Parentheses 33 Search in Rotated Sorted Array 44 Wildcard Matching Hard dp,backtrack 54 Spiral Matrix Medium array,s 72 Edit Distance Hard dp 74 Search a 2D Matrix Medium binary 91 Decode Ways Medium dp 108 Convert Sorted Array to Binary Search Tree Easy tree,dfs 109 Convert Sorted List to Binary Search Tree Medium tree,dfs 113 Path-Sum-II Medium tree,dfs 116 Populating Next Right Pointers in Each Node Medium tree 123 Best Time to Buy and Sell Stock III Hard dp,z 132 Palindrome Partitioning II Hard dp 134 gas-station Medium greedy 140 word-break-ii Hard dfs 142 Linked List Cycle II Medium list 188 Best Time to Buy and Sell Stock IV Hard dp,s 213 House Robber II Medium 236 Lowest Common Ancestor of a Binary Tree recursive 239 Sliding Window Maximum Hard doubleQueue 240 Search a 2D Matrix II Medium binary,z 253 Meeting Rooms II Medium 279 Perfect Squares Medium dp,math 283 Move Zeroes Easy 287 Find the Duplicate Number Medium arr,list,z 297 Serialize and Deserialize Binary Tree Hard tree 300 Longest Increasing Subsequence Medium 301 Remove Invalid Parentheses Hard DFS,z 312 Burst Balloons Hard dp,s,divide 309 Best Time to Buy and Sell Stock with Cooldown Medium dp,z,s 337 House Robber III Medium tree,dp 338 Counting Bits Medium b 347 Top K Frequent Elements Medium bucket sort 394 Decode String Medium tack,recursive 399 Evaluate Division Medium graph 406 Queue Reconstruction by Height Medium reedy,(bucket) 416 Partition Equal Subset Sum Medium dp 437 Path Sum III tree,s 438 Find All Anagrams in a String Easy string,s 448 Find All Numbers Disappeared in an Array Easy array,z 461 Hamming Distance b 486 Predict the Winner Medium dp 494 Target Sum dp,recursive 538 Convert BST to Greater Tree Easy tree 543 Diameter of Binary Tree Easy tree,s 560 Subarray Sum Equals K Easy z 572 Subtree of Another Tree Easy s 581 Shortest Unsorted Continuous Subarray Easy z 621 Task Scheduler Medium z 647 Palindromic Substrings Medium string,dp 877 Stone Game Medium 1012 Numbers With Repeated Digits Hard bit,math 1017 Convert to Base -2 Medium 1019 Next Greater Node In Linked List Medium b 1020 Number of Enclaves Medium stack 1022 Sum of Root To Leaf Binary Numbers Easy tree 1023 Camelcase Matching Medium string 1024 Video Stitching Medium array 1025 Divisor Game Easy z,math 1028 Recover a Tree From Preorder Traversal Hard s,tree,stack 1029 Two City Scheduling Easy sort,z 1031 Maximum Sum of Two Non-Overlapping Subarrays Medium dp,s 1032 Stream of Characters Medium trie 1035 Uncrossed Lines Medium dp,s 1039 Minimum Score Triangulation of Polygon Medium dp 1046 Last Stone Weight Easy array 1047 Remove All Adjacent Duplicates In String Easy stack 1048 Longest String Chain Medium dp,s 1049 Last Stone Weight II Medium dp 1078 Occurrences After Bigram Easy string 1081 Smallest Subsequence of Distinct Characters Medium string 1090 Largest Values From Labels Medium map 1092 Shortest Common Supersequence Hard string 1104 Path In Zigzag Labelled Binary Tree Easy tree,math 1105 Filling Bookcase Shelves Medium dp,s 1125 Smallest Sufficient Team Hard dp,b 1129 Shortest Path with Alternating Colors Medium bfs,graph 1130 Minimum Cost Tree From Leaf Values Medium greedy,tree 1131 Maximum of Absolute Value Expression Medium math 1138 Alphabet Board Path Medium 1140 Stone Game II Medium dfs 1144 Decrease Elements To Make Array Zigzag Easy array 1171 Remove Zero Sum Consecutive Nodes from Linked List Medium list 1175 Prime Arrangements Easy math 1178 Number of Valid Words for Each Puzzle Hard b 1187 Make Array Strictly Increasing Hard dp,LIS 1192 Critical Connections in a Network Hard graph 1219 Path with Maximum Gold Medium dfs C158 Weekly Contest 158 Hard dp C159 Weekly Contest 159 Hard dp z: 智商题 s: 比较固定且常见的 b: 二进制 commit: 为了之后方便归纳, 规定 commit 格式为 [题号] [难度(h|m|e)] [类别(数据结构|算法, 以空格分隔)]