C 语言版

#include<stdio.h>
#define N 100010

int n, ans, temp, nums[N];

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

}

int main()
{
    scanf("%d", &n);
    for(int i = 0; i < n; i++) scanf("%d", &nums[i]);
    quick_sort(0, n - 1);
    for(int i = 0; i < n / 2; i ++) ans += (nums[n - i - 1] - nums[i]);
    printf("%d", ans);
}