poj 3253 Fence Repair (哈夫曼树 优先队列)

题目：http://poj.org/problem?id=3253

没用long long wrong 了一次

 #include <iostream>
  #include<cstdio>
  #include<cstring>
  #include<cstdlib>
  #include<stack>
  #include<queue>
  #include<iomanip>
  #include<cmath>
  #include<algorithm>
  #include<map>
  using namespace std;

  int main()
  {
      long long n,i,j,a,sum,cnt;//或者 __int64 n,i,j,a,sum,cnt;
      priority_queue<int,vector<int>,greater<int> >pq;
      cin>>n;
      for(i=; i<n; i++)
      {
          cin>>a;
          pq.push(a);
      }
      sum=;
      while(!pq.empty())
      {
          cnt=pq.top();
          pq.pop();
          if(pq.empty())
          break;
          cnt+=pq.top();
          sum+=cnt;
          pq.pop();
          pq.push(cnt);
      }
      cout<<sum<<endl;
      return ;
  }