题解 | 学分绩点

#include<bits/stdc++.h>
using namespace std;

float GPA(int k)
{
    if(k>=90 && k<=100)return 4.0;
    else if(85<=k && k<=89)return 3.7;
    else if(k>=82&&k<=84)return 3.3;
    else if(k>=78&&k<=81)return 3.0;
    else if(k>=75&&k<=77)return 2.7;
    else if(k>=72&&k<=74)return 2.3;
    else if(k>=68&&k<=71)return 2.0;
    else if(k>=64&&k<=67)return 1.5;
    else if(k>=60&&k<=63)return 1.0;
    else
    {
        return 0.0;
    }
}

int main()
{
    int n;
    while(cin>>n)
    {
        int credit[n];
        int score[n];
        int sum = 0;
        double result;

        for(int i = 0;i<n;i++)
        {
            cin>>credit[i];
        }
        for(int i = 0;i<n;i++)
        {
            cin>>score[i];
        }
        for(int i = 0;i<n;i++)
        {
            sum += credit[i];
            result += credit[i]*GPA(score[i]);
        }
        result /= sum;
        printf("%.2f",result);

    }
    return 0;
}