LeetCode 75. Sort Colors

n

Here, we will use the integers 0, 1, and 2 to represent the color red, white, and blue respectively.

Note:

You are not suppose to use the library's sort function for this problem.

answer:

class Solution {
public:
    void sortColors(vector<int>& nums) {
        int end0 = -1, end1 = -1, end2 = -1;
        for(int i = 0; i < nums.size(); i ++){
            if(nums[i] == 0){
                nums[++end2] = 2;
                nums[++end1] = 1;
                nums[++end0] = 0;
            }
            else if(nums[i] == 1){
                nums[++end2] = 2;
                nums[++end1] = 1;
            }
            else nums[++end2] = 2;
        }
    }
};