hdoj1202简单题、模拟题

题目本身有问题。

首先学分和分数要求是实型的而不是整型的，这就要求用double，其次题目有个地方没说清楚，就是GPA不存在的情况，全都旷课算不存在，同时GPA为零也算不存在。

# 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; }}