题目思路

代码

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