Uva10954 Add All（哈夫曼编码问题）

#include<iostream>
#include <math.h>
#include<algorithm>
#include<vector>
#include<string>
using namespace std;
#include<queue>
priority_queue<int, vector<int>, greater<int> > q;//优先队列，按照指定排列队列大小
int main() {
	int n,ctn,num=0;
	int x, y;
	while (cin >> n && n) {
		num = 0;
		while (!q.empty()) q.pop();
		for (int i = 0; i < n; i++) {
			cin >> ctn;
			q.push(ctn);
		}
		for (int i = 0; i < n-1; i++) {
			x = q.top(); q.pop();
			y = q.top(); q.pop();
			q.push(x + y);
			num += x + y;
			
		}
		cout << num << endl;
	}
}