C :

#include<stdio.h>
int main()
{
	char c;
	scanf("%c",&c);
	switch(c)
	{
	case'a':
	case'A':printf("85~100");break;
	case'b':
	case'B':printf("70~84");break;
	case'c':
	case'C':printf("60~69");break;
	case'd':
	case'D':printf("0~60");break;
	}
	getchar();
	getchar();
	return 0;
}

C++ :

#include <iostream>
#include <cstdio>
using namespace std;
int main()
{
    char c;
    cin>>c;
    if(c>='a' && c<='Z')
    {
        //如果是小写，转成大写。
        c=c-32;
    }
    switch (c)
    {
        case 'A':
            cout<<"85~100"<<endl;
            break;
        case 'B':
            cout<<"70~84"<<endl;
            break;
        case 'C':
            cout<<"60~69"<<endl;
            break;
        case 'D':
            cout<<"0~60"<<endl;
            break;
    }
    return 0;
}