poj 3253 【哈夫曼树】【优先队列】

#include<iostream>
#include<queue>
using namespace std;

struct cmp1{
    bool operator ()(long long &a,long long &b){
        return a>b;//最小值优先
    }
};

    priority_queue<long long,vector<long long>,cmp1>pq;

int main(){
	long long n;
	while(cin>>n){
		long long a;
		long long ans=0;
		long long tempans=0;
		for(long long i=0;i<n;i++){
			cin>>a;
			pq.push(a);
		}
		while(pq.size()!=1){
			tempans+=pq.top();
			pq.pop();
			tempans+=pq.top();
			pq.pop();
			pq.push(tempans);
			ans+=tempans;
			tempans=0;
		}
		cout<<ans<<endl;
	}
}