[LeetCode]75. Sort Colors

[LeetCode]75. Sort Colors

题目描述

思路

只有三个数字，可以用快排简化版，确定支点为1
进一步，更简单的方法，扫描一次获取每个数字的个数即可

代码

class Solution {
public:
    void sortColors(vector<int>& nums) {
        int count_0 = 0, count_1 = 0;
        for (int &p : nums) {
            if (p == 0)
                ++count_0;
            if (p == 1)
                ++count_1;
        }
        for (int i = 0; i < nums.size(); ++i) {
            if (i < count_0)
                nums[i] = 0;
            else if (i >= count_0 && i <count_0 + count_1)
                nums[i] = 1;
            else
                nums[i] = 2;
        }
    }
};