小宝的实验四-在分支循环结构中调用自定义函数

//计算多个用户的电费
#include<stdio.h>
int main()
{
    int i,n;
    double x,y;
    double fee(double x);

    printf("Enter n:");
    scanf("%d",&n);

    for(i=1;i<=n;i++)
    {
        printf("Enter x:");
        scanf("%lf",&x);

        if(x<=0)
            printf("输入错误，重新输入");
        else{
            y=fee(x);
        }
        printf("y=%.3f
",y);
    }
    return 0;
}
double fee(double x)
{
    double y;
        if(x<=50)
        {
            y=0.53*x;
        }
        else
        {
            y=26.5+0.58*(x-50);
        }
    return y;
}

//计算并输出该用户应支付的电费
#include<stdio.h>
int main(void)
{
    int n,i;
    double x,y;

    printf("Enter n:");
    scanf("%d",&n);

    for(i=1;i<=n;i++)
    {
        printf("Enter x=:");
        scanf("%lf",&x);

        if(x<=0)
        {
            printf("输入错误，重新输入");
        }
        else 
            if(x<=50)
        {
            y=0.53*x;
        }
        else
        {
            y=26.5+0.58*(x-50);
        }
        printf("y=f(%f)=%.2f
",x,y);

    }
    return 0;
}

//利用循环计算多个圆柱体体积
#include<stdio.h>
#define PI 3.14
int main()
{
    int h,r,n,i;
    double v;
    double cylinder(int r,int h);

    printf("Enter n=:");
    scanf("%d",&n);

    for(i=1;i<=n;i++){
        printf("Enter r and h:
");
        scanf("%d%d",&r,&h);
        if((r<=0)||(h<=0))
        {
            printf("输入错误，重新输入");
        }
        else{
            v=cylinder(r,h);
            printf("V=%.3f
",v);
        }
    }

    return 0;
}
double cylinder(int r,int h)
{
    double result;

    result=PI*r*r*h;

    return result;
}