C++ 代码

#include <iostream>
#include <algorithm>

using namespace std;

const int N = 100010;

int n;
int a[N];

int main()
{
    cin >> n;
    for (int i = 0; i < n; i ++ ) scanf("%d", &a[i]);
    sort(a, a + n);

    int res = 0;
    for(int i = 0; i < n;  i += 2) res += abs(a[i] - a[i + 1]);
    cout << res << endl;
}