每天刷5道题打卡贴！

----09/15/2019----

Two pointers:
- 167. Two Sum II - Input array is sorted


String:
- 43. Multiply Strings

Array:
- 54. Spiral Matrix
- 289. Game of Life
- 643. Maximum Average Subarray I1,

----09/18/2019----

238. Product of Array Except Self        Array
152. Maximum Product Subarray        Array, DP
697. Degree of an Array        Array
46. Permutations        DFS
47. Permutations II        DFS
77. Combinations        DFS
39. Combination Sum        DFS
40. Combination Sum II        DFS
937. Reorder Data in Log Files        String

----10/14/2019----

328. Odd Even Linked List        Linked List
122. Best Time to Buy and Sell Stock II        Greedy
378. Kth Smallest Element in a Sorted Matrix        Binary Search
141. Linked List Cycle        Linked List, Two Pointers
19. Remove Nth Node From End of List        Linked List, Two Pointers
127. Word Ladder        BFS

上一条应该是09/16哈

----09/17/2019----

Two Pointers:
- 76. Minimum Window Substring
- 283. Move Zeroes

Sort:
- 179. Largest Number

Queue:
- 346. Moving Average from Data Stream

Hash Table:
- 387. First Unique Character in a String
- 347. Top K Frequent Elements

Heap:
- 973. K Closest Points to Origin

Design:
- 225. Implement Stack using Queues
- 380. Insert Delete GetRandom O(1) ***

dp:
- 10. Regular Expression Matching ***

----09/15/2019----

Tree:
- 124. Binary Tree Maximum Path Sum
- 98. Validate Binary Search Tree
- 173. Binary Search Tree Iterator (stack, design)
- 543. Diameter of Binary Tree
- 236. Lowest Common Ancestor of a Binary Tree

Array:
- 53. Maximum Subarray (dp)

Binary Search:
- 33. Search in Rotated Sorted Array

Two Pointers:
- 3. Longest Substring Without Repeating Characters (hash table)

加油＾０＾~

加油 楼主

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加油！！！

----09/19/2019----

23. Merge k Sorted Lists        Divide and Conquer
264. Ugly Number II        Heap
232. Implement Queue using Stacks        Stack, Design
251. Flatten 2D Vector        Design
299. Bulls and Cows        Hash Table
819. Most Common Word        String