刷题记录

3/28/18

今天共刷题16道,复习50道，学习9h06m

Easy:

• 729. My Calendar I
• 167. Two Sum II - Input array is sorted
• 270. Closest Binary Search Tree Value
  

Medium:

• 81. Search in Rotated Sorted Array II
• 390. Elimination Game
• 260. Single Number III
• 694. Number of Distinct Islands
• 285. Inorder Successor in BST
• 442. Find All Duplicates in an Array
• 153. Find Minimum in Rotated Sorted Array
• 162. Find Peak Element
• 209. Minimum Size Subarray Sum
• 222. Count Complete Tree Nodes
• 230. Kth Smallest Element in a BST
  

Hard:

• 154. Find Minimum in Rotated Sorted Array II
• 174. Dungeon Game
  

222. Count Complete Tree Nodes这道题一直tle，仔细看发现getHeight这一步取得是左子树的高度，并非整棵树的高度，以前一直忽视了。看来还是要实打实的敲一遍，才能发现问题，很多题以为自己会了，其实还是有没搞透的地方。

要加油了，开始准备狗家店面了

3/29/18

今天共刷题11道,复习50道，学习6h32m

Easy:

• 766. Toeplitz Matrix
• 733. Flood Fill
• 278. First Bad Version
  

Medium:

• 421. Maximum XOR of Two Numbers in an Array
• 373. Find K Pairs with Smallest Sums
• 393. UTF-8 Validation
• 82. Remove Duplicates from Sorted List II
• 279. Perfect Squares
• 39. Combination Sum
• 275. H-Index II
  

Hard:

• 768. Max Chunks To Make Sorted II
  

今天进行了mock interview，觉得自己还是有差距，做题速度需要加强，三周倒计时，加油加油加油

3/30/18
今天共刷题2道,复习50道，学习5h42m

Easy:

• 232. Implement Queue using Stacks
  

Medium:

• 165. Compare Version Numbers
  

今天没有怎么刷新的题，只是复习了旧题，又看了下背包问题6题并做了总结，对于分治法也想看看总结，感觉总结类的资料性价比很高~

4/1/18

今天共刷题7道,复习50道，学习4h44m

Easy:

• 349. Intersection of Two Arrays
  

Medium:

• 8. String to Integer (atoi)
• 241. Different Ways to Add Parentheses
• 777. Swap Adjacent in LR String
• 684. Redundant Connection
• 406. Queue Reconstruction by Height
  

Hard:

• 302. Smallest Rectangle Enclosing Black Pixels
  

777. Swap Adjacent in LR String 本来想用dfs解，但是答案用two pointer的方法也很巧妙呀

昨天和今天都去打球了，突然这么高强度运动真不习惯。。笔都握不住了

4/2/18
今天共复习50道，学习5h45m

早上发现了有个帖子做了很好的题目分类http://www.1point3acres.com/bbs/thread-380779-1-1.html
https://docs.google.com/spreadsheets/d/1I_fyfIoWEXtHJD32BmVXxj_tishqU7Rd8GqUpRgxhks/edit#gid=0

打算把自己整理的总结与这个帖子中的整合一下，以后复习的时候就可以提高效率啦

4/3/18
今天共刷题8道,复习51道，学习5h44m

Medium:

• 286. Walls and Gates
• 133. Clone Graph
• 377. Combination Sum IV
• 535. Encode and Decode TinyURL
  

Hard:

• Word Break II
• 768. Max Chunks To Make Sorted II
• 354. Russian Doll Envelopes
• 363. Max Sum of Rectangle No Larger Than K
  

4/4/18

今天共刷题14道,复习47道，学习8h44m

Easy:

• 530. Minimum Absolute Difference in BST
• 246. Strobogrammatic Number
• 551. Student Attendance Record I
• 401. Binary Watch
  

Medium:

• 274. H-Index
• 46. Permutations
• 779. K-th Symbol in Grammar
• 17. Letter Combinations of a Phone Number
• 22. Generate Parentheses
• 78. Subsets
• 491. Increasing Subsequences
• 47. Permutations II
• 518.Coin Change II
• 322.Coin Change
  

主要刷了下经典的backtracking， 779真是费脑筋。。

4/5/18 ~ 4/6/18

非常感谢之前那个发文档的同学，在他的基础上，我又做了一些细化的分类和补充，昨天和今天做了binary search的分类以及 部分的BFS/DFS。
先贴BS的吧。

Binary Search

Range Search               

• 34        Search for a Range
• 74        Search a 2D Matrix
• 658        Find K Closest Elements
• 302        Smallest Rectangle Enclosing Black Pixels
• 240        Search a 2D Matrix II
  

Rotated Sorted Array                

• 33        Search in Rotated Sorted Array
• 81        Search in Rotated Sorted Array II
• 153        Find Minimum in Rotated Sorted Array
• 154        Find Minimum in Rotated Sorted Array II
  

Merge Sort                

• 315        Count of Smaller Numbers After Self
• 327        Count of Range Sum
• 493        Reverse Pairs
• 775        Global and Local Inversions
  

Binary Search Guess                

• 410        Split Array Largest Sum
• 540        Single Element in a Sorted Array
• 644        Maximum Average Subarray II
• 378        Kth Smallest Element in a Sorted Matrix
• 719        Find K-th Smallest Pair Distance
  

MergeSort 和 Binary Search Guess 都有不少难题，但是总结出套路就事半功倍了

4/7/18 ~ 4/9/18

这两天把图的题总结了下，可能没有囊括所有的题，不过每个种类二到三题也基本能看出套路。

Games(Game)        

• 36        Valid Sudoku
• 37        Sudoku Solver
• 488        Zuma Game
• 51        N-Queens
• 52        N-Queens II
• 351        Android Unlock Patterns
• 679        24 Game
  

Abbreviation(Abbr)                

• 408        Valid Word Abbreviation
• 288        Unique Word Abbreviation
• 320        Generalized Abbreviation
• 411        Minimum Unique Word Abbreviation
• 527        Word Abbreviation
  

Backtracking

• 17        Letter Combinations of a Phone Number
• 401        Binary Watch
• 22        Generate Parentheses
• 78        Subsets
• 90        Subsets II
• 46        Permutations
• 47        Permutations II
• 77        Combinations
• 39        Combination Sum
• 40        Combination Sum II
• 216        Combination Sum III
• 377        Combination Sum IV
• 267        Palindrome Permutation II
• 526        Beautiful Arrangement
• 254        Factor Combinations
• 491        Increasing Subsequences
• 282        Expression Add Operators
• 131        Palindrome Partitioning
• 638        Shopping Offers
• 473        Matchsticks to Square
• 301        Remove Invalid Parentheses
• 399        Evaluate Division
  

Check Status                

• 468        Validate IP Address
• 93        Restore IP Addresses
• 132        Palindrome Partitioning II
• 422        Valid Word Square
  

Bidirectional BFS                

• 127        Word Ladder
• 126        Word Ladder II
• 433        Minimum Genetic Mutation
  

Trie                

• 79        Word Search
• 212        Word Search II
• 425        Word Squares
  

Islands        

• 200        Number of Islands
• 305        Number of Islands II
• 694        Number of Distinct Islands
• Number of Distinct Islands II
  

Maze        

• 490        The Maze
• 505        The Maze II
• 499        The Maze III
  

Update Status        

• 130        Surrounded Regions
• 417        Pacific Atlantic Water Flow
• 529        Minesweeper
  

Shortest Distance                

• 317        Shortest Distance from All Buildings
• 286  Walls and Gates
• 505        The Maze II
• 499        The Maze III
  

ab to 12(AbTo12)        

• 205        Isomorphic Strings
• 290        Word Pattern
• 291        Word Pattern II
• 734        Sentence Similarity
  

others

• 582  Kill Process
• 419  Battleships in a Board
• 332 Reconstruct Itinerary
• 690 Employee Importance
  

4/10 ~ 4/11

这两天总结了了DP的分类，真是死了不知道多少脑细胞，尤其是out of box那个类别，真心想不出来。。。

差不多还有一周就要电面了，接下来着重看面经了

Dynamic Programming

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
• 309        Best Time to Buy and Sell Stock with Cooldown
• 741        Best Time to Buy and Sell Stock with Transaction Fee
• 53        Maximum Subarray
• 152        Maximum Product Subarray
  

O(n) DP, O(1) Space, Fibonacci

• 70        Climbing Stairs
• 91        Decode Ways
• 639        Decode Ways II
• 198        House Robber
• 213        House Robber II
• 337        House Robber III
• 256        Paint House
• 265        Paint House II
• 276        Paint Fence
• 600        Non-negative Integers without Consecutive Ones
  

O(mn) DP,O(n) Space

• 494        Target Sum
• 673        Number of Longest Increasing Subsequence
• 96        Unique Binary Search Trees
• 95        Unique Binary Search Trees II
• 279        Perfect Squares
• 322        Coin Change
• 343        Integer Break
• 139        Word Break
• 140        Word Break II
• 120        Triangle
• 62        Unique Paths
• 63        Unique Paths II
• 562        Longest Line of Consecutive One in Matrix
• 221        Maximal Square
• 64        Minimum Path Sum
• 174        Dungeon Game
• 551        Student Attendance Record I
• 238        Product of Array Except Self
• 321        Create Maximum Number
• 363        Max Sum of Rectangle No Larger Than K
• 354        Russian Doll Envelopes
• 368        Largest Divisible Subset
• 410        Split Array Largest Sum
• 416        Partition Equal Subset Sum
• 403        Frog Jump
• 413        Arithmetic Slices
• 467        Unique Substrings in Wraparound String
  

O(mn) DP, O(mn) Space

• 361        Bomb Enemy
• 303        Range Sum Query - Immutable
• 304        Range Sum Query 2D - Immutable
• 474        Ones and Zeroes
• 516        Longest Palindromic Subsequence
  

String Matching

• 44        Wildcard Matching
• 10        Regular Expression Matching
• 72        Edit Distance
• 87        Scramble String
• 97        Interleaving String
• 583        Delete Operation for Two Strings
• 115        Distinct Subsequences
  

Game

• 294        Flip Game II
• 464        Can I Win
• 486        Predict the Winner
  

Out of box

• 312        Burst Balloons
• 466        Count The Repetitions
• 472        Concatenated Words
• 514        Freedom Trail
• 517        Super Washing Machines
• 546        Remove Boxes
• 471        Encode String with Shortest Length
• 576        Out of Boundary Paths
• 629        K Inverse Pairs Array
• 446        Arithmetic Slices II - Subsequence
• 568        Maximum Vacation Days
• 552        Student Attendance Record II
• 600        Non-negative Integers without Consecutive Ones
  

Backpack

• lintcode 6题