题解 | #寻找第K大#

class Solution {
public:
    
    void swap(int *p, int *q){
        int temp = *p;
        *p = *q;
        *q = temp;
    }
    
    void my_qsort(vector<int> &arr, int i, int j){
        int size = arr.size();
        int start = i, end = j;
        int temp = arr[i];
        if(i>=j) return;
        while(i<j){
            while(i<j&&arr[j]<temp){
                j--;
            }
            swap(&arr[i], &arr[j]);
            i++;
            
            while(i<j&&arr[i]>temp){
                i++;
            }
            swap(&arr[i], &arr[j]);
            j--;
        }
        
        my_qsort(arr,start, i-1);
        my_qsort(arr,j+1, end);
    }
    
    int findKth(vector<int> a, int n, int K) {
        int size = a.size();
        my_qsort(a, 0,n-1);
        return a[K-1];
    }
};