题解 | #牛群的排序#快排

class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param nums int整型vector 
     * @return int整型vector
     */

    void swap(int& a, int &b){
        int tmp = a;
        a = b;
        b = tmp;
    }

    void quickSort(vector<int>& nums, int head, int rear){
        if(head >= rear) return;
        int pivot = nums.at(head);
        int indexL = head; int indexR = rear;

        while(indexL < indexR){
            while(nums[indexR] >= pivot && indexR > indexL) indexR--;
            while(nums[indexL] <= pivot && indexL < indexR) indexL++;
            if(indexL < indexR) swap(nums.at(indexL), nums.at(indexR));
        }

        swap(nums.at(head), nums.at(indexL));
        quickSort(nums, head, indexL - 1);
        quickSort(nums, indexR + 1, rear);
    }

    vector<int> sortCows(vector<int>& nums) {
        quickSort(nums, 0, nums.size() - 1);
        return nums;
    }
};