Leetcode Weekly Contest 257

没啥可说的，看错题了，直接崩溃

T1: Count Special Quadruplets

暴力统计

T2: The Number of Weak Characters in the Game

排序统计

T3: First Day Where You Have Been in All the Rooms

是次数！次数次数！！！

T4: GCD Sort of an Array

GCD排序，置换群原理，先并查集预处理，然后判断是否在置换中