hdoj1202簡單題、類比題

題目本身有問題。

首先學分和分數要求是實型的而不是整型的，這就要求用double，其次題目有個地方沒說清楚，就是GPA不存在的情況，全都曠課算不存在，同時GPA為零也算不存在。

# include <iostream># include <iomanip>using namespace std;void main(){ int n; while(cin>>n) {  double credit,score;  double count=0.0,credsum=0.0;  while(n-- > 0)  {   cin>>credit>>score;   if(score != -1)    credsum+=credit;   if(score>=90)    count+=credit*4;   else if(score>=80)    count+=credit*3;   else if(score>=70)    count+=credit*2;   else if(score>=60)    count+=credit*1;  }  if(credsum == 0 || count==0) cout<<"-1"<<endl;  else   cout<<fixed<<setprecision(2)<<count/credsum<<endl; }}