#include "stdio.h"
main()
{
    char x,y;       //x:服务种类y:油品种类
    double s,p;        //总价格
    printf("请输入加油量\n");
    scanf("%lf",&p);
    printf("选择自动加油按A，选择手动加油按B\n");
    scanf("%C",&x);
    printf("有a,b,c三种油，a:6.12元,b:5.95元,c:5.75元\n");
    switch(x)
    {
    case'A':
        {
            printf("选择油品种类\n");
            scanf("%c",&y);
            switch(y)
            {
            case'a':s=p*6.12*0.98;break;
            case'b':s=p*5.95*0.98;break;
            case'c':s=p*5.75*0.98;break;
            }
        }
    case'B':
        {
            printf("选择油品种类\n");
            scanf("%c",&y);
            switch(y)
            {
            case'a':s=p*6.12*0.95;break;
            case'b':s=p*5.95*0.95;break;
            case'c':s=p*5.75*0.95;break;
            }
        }
    }
    printf("需要付款:%f",s);
}

是第五题

小白一枚

用If比较好吧
#include "stdio.h"
void Ck_Ty(char y,double p)//传入参数油类型，加油量
{    double sum;
    if(y=='a')
    {sum=p*6.12*0.98;
        printf("总%lf",sum);
    }else if(y=='b')
    {    sum=p*5.95*0.95;
        printf("总%lf",sum);
    }else if(y=='c')
    {    sum=p*5.75*0.98;
        printf("总%lf",sum);
    }else
        printf("无相关类型！");

}
int main()
{

   
    char y;
    double p;
    char  x;       //x:服务种类y:油品种类
//    double s;        //总价格
   printf("请输入加油量\n");
    scanf(" %lf",&p);
    printf("选择自动加油按A,选择手动加油按B\n");
    scanf(" %c",&y);
    switch(y)
    {
    case 'A':{printf("有a,b,c三种油，a:6.12元,b:5.95元,c:5.75元\n");
    scanf(" %c",&x);
    Ck_Ty(x,p);}break;
    case 'B':{printf("有a,b,c三种油，a:6.12元,b:5.95元,c:5.75元\n");
    scanf(" %c",&x);
    Ck_Ty(x,p);}break;
    default:printf("请输入A或B!");
    }
    return 0;
}

[此贴子已经被作者于2018-10-26 18:13编辑过]