题解 | #排序#

import java.util.*;


public class Solution {
   
    public int[] MySort (int[] arr) {
        quick_sort(arr, 0, arr.length - 1);  //注意数组越界
        return arr;
    }

    public void quick_sort(int[] q, int l, int r){
        if(l >= r)
            return;
        int x = q[l + r >> 1], i = l - 1, j  = r + 1;
        while(i < j){
            while(q[++ i] < x );
            while(q[-- j] > x );
            if(i < j){
                q[i] = (q[i] + q[j]) - (q[j] = q[i]);
            }
        }
        
        quick_sort(q, l, j);
        quick_sort(q, j + 1, r);
    }
}