算法基础课模版「随听随更」

1.快速排序

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

}

2.归并排序