hdu4802

水题反映一个问题。。。。我很不认真。。。

题目

#include<iostream>#include<stdio.h>#include<string>using namespace std;int main(){double sum,sumc,c,s[14]={4.0,3.7,3.3,3.0,2.7,2.3,2.0,1.7,1.3,1.0,0.0};string ch[14]={"A","A-","B+","B","B-","C+","C","C-","D","D-","F"},str;int n;while(cin>>n){sum=0;sumc=0;for(int i=0;i<n;i++){cin>>c>>str;if(str=="P"||str=="N")continue;for(int j=0;j<14;j++){if(str==ch[j]){sum+=(1.0*s[j]*c);sumc+=c;break;}}}sum=1.0*sum/sumc;if(sumc==0) cout<<"0.00"<<endl;else printf("%.2lf\n",sum);}}