暂定以 E E E M M H(M) 的顺序做题
组内所有人完成代码并提交后进入下一题
不强制要求完成，暂定无惩罚
E 344. Reverse String
E 412. Fizz Buzz
E 104. Maximum Depth of Binary Tree
M 238. Product of Array Except Self
M 046. Permutations
H 042. Trapping Rain Water
E 136. Single Number
E 283. Move Zeroes
E 206. Reverse Linked List
M 454. 4Sum II
M 230. Kth Smallest Element in a BST
M 938. Range Sum of BST
E 067. Add Binary
M 005. Longest Palindromic Substring
M 047. Permutations II