打卡

10.29
Q: passed in as a parameter or make as a class member?

10.30
一场mock
看一下s司的帖子，了解下它们screnning的流程
把set的疑惑点搞清楚（robot vs stones）
做三道题permutation2看一下别人的答案

10.30
Move Zeroes
Permutations II
mock 了一场

10.31
mock了一场
Valid Square
Rotating the Box

补充内容 (2021-11-01 10:20 +8:00):
Flatten Binary Tree to Linked List

补充内容 (2021-11-01 11:24 +8:00):
17. Letter Combinations of a Phone Number

补充内容 (2021-11-01 13:44 +8:00):
Rank Teams by Votes

补充内容 (2021-11-01 13:56 +8:00):
Kth Largest Element in an Array

11.2
Nested List Weight Sum
Nested List Weight Sum II
Valid Parentheses
Factor Combinations
mock 了一场

11.3
Valid Parentheses
Merge Intervals
Maximum Product Subarray
Maximum Subarray

11.4
Implement Trie (Prefix Tree)

总结一下解体思路：
step1 : 先自己想不同的test cases -> 其实也是为了了解题目
step2: 从给的，和自己想的test cases开始，从 brute force 出发，一步一步分析用什么 ds 和 algo
step3：用 step2 的方法去跑 test cases；有时间的话，简单说下 complexity
step4：开始写，边写边说
step5：用 step4 写的 code 再跑一遍 test cases

tree:

q1: when choose the base case of the recursion, null node or the node without children?

补充内容 (2021-11-08 13:21 +8:00):
a1: depends on the case
case1: return a list of leaf nodes, then the base case should be node without children
case2: other

mock 的总结
1. try to think of all test cases
2. when interviewer try to give hints, take it!
3. when declare a var, write down 3.1) the meaning (definition) / name it so it is self-explaining and 3.2) an example
4. when declare a function, write down 4.1) signature (input, output, function name) and 4.2) the major steps