使用优先队列解决（所有叶结点的值与权值（到根的路径长度）的乘积之和=非叶子节点之和）

升序队列，小顶堆：priority_queue <int,vector<int>,greater<int> > q;

降序队列，大顶堆：priority_queue <int,vector<int>,less<int> >q;

#include <bits/stdc++.h>

using namespace std;

int main(){
    int n;
    while(cin >> n){
        priority_queue<int, vector<int>, greater<int> > q;
        for(int i = 0 ; i < n; i++){
            int x;
            cin >> x;
            q.push(x);
        }
        int a,b,ans=0;
        while(q.size()!=1){
            a = q.top();
            q.pop();
            b = q.top();
            q.pop();
            a = a+b;
            ans += a;
            q.push(a);
        }
        cout << ans << endl;
    }
    return 0;
}