只能过一个点的看过了，我来告诉你原因

#include <iostream>
#include <algorithm>
#define swap(a,b) std::swap(a,b)
int heap[10010];
int n;
void down(int i){
  int t=0,flag=0;
  while(i*2<n && !flag){
    if(heap[i]>heap[i*2]){
      t=i*2;
    }
    else{
      t=i;
    }
    if(i*2+1<n){
      if(heap[t]>heap[i*2+1]){
        t=i*2+1;
      }
    }
    if(i!=t){
      swap(heap[t],heap[i]);
      i=t;
    }else{
      flag=1;
    }
  }
  return ;
}
void buildheap(){
  for(int i=n/2;i>=0;i--)
    down(i);
  return ;
}
int delmin(){
  int ret=heap[0];
  swap(heap[0],heap[n-1]);
  heap[n-1]=0;n--;
  down(0);
  return ret;
}
void insert(int x){
  heap[n]=x;
  down(n);
  int i=n;
  while(i>0){
    if(heap[i]<heap[i/2]){
      swap(heap[i],heap[i/2]);
      i/=2;
    }else{
      break;
    }
  }
  n++;
}
int main(int argc, char const *argv[]) {
  std::cin >> n;
  for(int i=0;i<n;i++)
    std::cin >> heap[i];
  buildheap();
  int work=0;
  int a,b;
  while(n>0){
    if(n==1){
      break;
    }
    a=delmin();b=delmin();
    work+=(a+b);
    insert(a+b);
  }
  std::cout << work << '\n';
  return 0;
}