小弟是初学者  深知论坛卧虎藏龙 有些代码不知道哪个地方出错了希望给看一下 每次总是输出的时候出错 不管输入什么都是出来的0.000很是疑惑不解 希望一下 感激不尽！
顺便一提我用的是win7 用的编译器是win-tc！本代码纯属是为了 巩固所学的内容

代码如下：


#include<stdio.h>
#include<math.h>
#include<stdlib.h>
void main()
{
    int choice;
    int year;
    double a,b,c,area,s,max;
    char oper;
    printf("* * * * * * * * Menu * * * * * * * *\n");
    printf("*      1.The biggest number        *\n");
    printf("*      2.Reconize the leap year    *\n");
    printf("*      3.The area of the triangle  *\n");
    printf("*      4.Simple calculation        *\n");
    printf("*      0.Exit                      *\n");
    printf("* * * * * * * * * * * * * * * * * * *\n");
    printf("Please select(0-4):");
    scanf("%d",&choice);
    switch(choice)
    {
    case 1:
        printf("Please input number(a,b,c):");
        scanf("%f%f%f",&a,&b,&c);
        if (a>b)
            {if (a>c)
                max=a;
            else
                max=c;
            }
            else
                {if (b>c)
                    max=b;
                else
                    max=c;
                }
                printf("The max nimber is %f\n",max);
                break;
    case 2:
        printf("Please input the year:");
        scanf("%d",&year);
        if ((year%4==0)&&(year%100!=0)||(year%400==0))
            printf("%4d is a leap year",year);
        else
            printf("%4d is not a leap year",year);
        break;
    case 3:
        printf("Please input a,b,c:");
        scanf("%f%f%f",&a,&b,&c);
        if (a<=0||b<=0||c<=0||a+b<c||b+c<a||a+c<b)
            printf("data error!\n");
        else
        {
            s=(a+b+c)/2;
            area=sqrt(s*(s-a)*(s-b)*(s-c));
            printf("area=%f",area);
        }
        break;
    case 4:
        printf("input expression[a op b]:");
        scanf("%f%c%f",&a,&oper,&b);
        switch(oper)
        {
        case '+':
            printf("%5.1f%c%5.1f=%5.1f\n",a,oper,b,a+b);
            break;
        case '-':
            printf("%5.1f%c%5.1f=%5.1f\n",a,oper,b,a-b);
            break;
        case '*':
            printf("%5.1f%c%5.1f=%5.1f\n",a,oper,b,a*b);
            break;
        case '/':
            printf("%5.1f%c%5.1f=%5.1f\n",a,oper,b,a/b);
            break;
        default:printf("input error!\n");
        }
        break;
        case 0 :
            exit(0);
            break;
        default:printf("error!\n");

    }
    getch();
}
谢谢
有什么错误还请一定要指出来！