75.cpp

class Solution {
public:
    void sortColors(vector<int>& nums) {
        int zeroI = 0, secndI = nums.size() - 1;
        for(int i = 0; i < nums.size(); i++) {
            while (nums[i] == 2 && i < secndI) swap(nums[i], nums[secndI--]);
            while (nums[i] == 0 && i > zeroI) swap(nums[i], nums[zeroI++]);
        }
    }
};