优先队列（类似于合并石子）

#include<iostream>
#include<queue>

using namespace std;

using namespace std;

int n;
priority_queue<int, vector<int>, greater<int>> q;

int main()
{
    cin >> n;
    for ( int i = 1; i <= n; i ++ )
    {
        int x;
        cin >> x;
        q.push(x);
    }

    int res = 0;
    while (q.size() > 1)
    {
        int a = q.top();q.pop();
        int b = q.top();q.pop();
        res += a + b;
        q.push(a + b);
    }

    cout << res << endl;

    return 0;
}