杭电acm1202 求GPA

#include
#include
using namespace std;
int main()  
{  
    int t;  
    while(cin>>t)  
    {  
        double n,m,sum1=0,sum2=0;  //sum1求学分和，sum2求学分乘绩点和 
        while(t--)  
        {  
            cin>>n>>m;  
            if(m==-1)  
            continue;  
            sum1+=n;  
            if(m>=90) m=4;  
            else if(m>=80) m=3;  
            else if(m>=70) m=2;  
            else if(m>=60) m=1;  
            else if(m<60) m=0;  
            sum2+=m*n;  
        }  
        if(sum1<=0||sum2<=0)  
        {  
            cout<<"-1"<continue;  
        }
        cout<2)<<std::fixed<return 0;  
}