Description
Submission
class Solution { public: void sortColors(vector<int>& nums) { if(nums.size() == 1) return; int p0 = 0, p2 = nums.size() - 1; for(int i = 0; i <= p2;) { if(nums[i] == 0) { swap(nums[i++], nums[p0++]); } else if(nums[i] == 2) { swap(nums[i], nums[p2--]); } else { ++i; } } } };