HDU4802_GPA

水题。

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

double totsum,totnum,k;
char s[5];
int n;

double get()
{
    if (s[0]=='A')
    {
        if (s[1]==0) return 4;
        else return 3.7;
    }
    if (s[0]=='B')
    {
        if (s[1]==0) return 3;
        else if (s[1]=='+') return 3.3;
        else return 2.7;
    }
    if (s[0]=='C')
    {
        if (s[1]==0) return 2;
        else if (s[1]=='+') return 2.3;
        else return 1.7;
    }
    if (s[0]=='D')
    {
        if (s[1]==0) return 1.3;
        else return 1;
    }
    if (s[0]=='F') return 0;
    return -1;
}

int main()
{
    while (scanf("%d",&n)!=EOF)
    {
        totsum=totnum=0;
        while (n--)
        {
            scanf("%lf%s",&k,s);
            double tep=get(); //cout<<" this is : "<<tep<<endl;
            if (tep<0) continue;
            totnum+=k;
            totsum+=k*tep;
        }
        if (totnum==0) printf("0.00
");
            else printf("%.2f
",totsum/totnum);
    }
    return 0;
}