这是一个优先队列的题啊...

#include <bits/stdc++.h>
using namespace std;

const int MAXN = 20010;

int n, b = 0, c = 0, a[MAXN];

int main() {
	priority_queue<int> q;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> a[i];
		q.push(-a[i]);
	}
	while (!q.empty()) {
		if (q.size() == 1) {
			break;
		}
		b = abs(q.top());
		q.pop();
		b += abs(q.top());
		q.pop();
		c += b;
		q.push(-b);
	}
	cout << c;
	return 0;
}