用priority_queue把輸入由小排到大，在queue剩一個資料之前，執行合併最小的兩個數字，累加至ans，接著再推入合併的值

4

10 11 12 13 //測資 答案為92 非100

#include <iostream> 
#include <algorithm>
#include <vector>
#include <queue>
#define fast_as_a_fuckboy ios_base::sync_with_stdio(0);cin.tie(0);
using namespace std;

int main(){
  fast_as_a_fuckboy; 
  int num;
  long long int n, ans;
  while(cin >> n && n != 0){
    priority_queue<long long,vector<long long>,greater<long long>> pq;
    ans = 0;
    for(int i = 0; i < n; i++){
      cin >> num;
      pq.push(num);
    }
    long long int sum; 
    while(pq.size() > 1){
      long long int first = pq.top();
      pq.pop();
      long long int second = pq.top();
      pq.pop();
      sum = first + second;
      ans += sum;
      pq.push(sum);
    }
    cout << ans << "\n";
  }
}