[第三期活动] 在职刷题打卡，目标工作日一天2题，周末一天5题

day 2
Alien Dictionary 今儿写的不多，不过这题hard写完打败了98，很开心了！
Minimum Height Trees

Day_2 (9/2)
Copy list with random pointer  // O(1) space
Min stack

Day 1
maximize distance to closest person, more like coming up with edge cases
top k frequent words, top k frequent elements, hashmap + min heap
meeting rooms II, the idea of thinking in terms of room but not meeting
insert delete get random O(1), hashmap + array
jump game i, just need to understand the problem
department top three salaries, did not do any sql question before, the way how they approach it is very programmatically rather than using sql's built in fn
jump game ii, dp & bfs => O(n^2) but TLE

#Day_02

2题 + 看面经
Binary Tree Inorder Traversal
Longest Increasing Subsequence

#Day_02
Lowest Common Ancestor of a Binary Tree
Exclusive Time of Function
Best Meeting Point
Insert Delete GetRandom O(1)
Expression Add Operators

#Day_02

打算重新刷一遍刷过的题. 按分类刷。
分类：Array
238. Product of Array Except Self
56. Merge Intervals
53. Maximum Subarray

补一下昨天
#Day_01
Pow(x, n)
Random Pick with Weight
Longest Consecutive Sequence
Best time to  Buy and Sell Stock III
Word Ladder II

刚加入，补一下昨天的
#day 1#finished 5

1007. Minimum Domino Rotations For Equal Row
1161. Maximum Level Sum of a Binary Tree
289. Game of Life
692. Top K Frequent Words
1002. Find Common Characters

day 1
5题，都是图论
Evaluate Division
Course Schedule II
Course Schedule
Graph Valid Tree
Number of Connected Components in an Undirected Graph

Day_1 (9/1)

Group Anagrams
Longest substring without repeating characters
Binary tree vertical order traversal
Binary tree zigzag level order traversal
Guess number higher or lower