杭电ACM1096求和问题

#include <iostream>using namespace std;int main(){    int n,m,a,sum=0;    while(cin>>n)    {        while (n--)        {            cin>>m;            sum=0;            while (m--)            {                cin>>a;                sum=sum+a;            }            if(n>0)            cout<<sum<<endl<<endl;            else            cout<<sum<<endl;        }    }    return 0;}