题75. 颜色分类

C++

class Solution { public: void sortColors(vector<int>& nums) { int head = 0; int tail = nums.size()-1; for(int i =0;i<=tail;i++){ if(nums[i] == 0){ swap(nums[head++],nums[i]); } else if(nums[i] == 2){ swap(nums[i--],nums[ta