#include "iostream.h"
int main()
{
    int a,b,c;
    char aper,count;
    cout<<"输入日期(如:2005-2-8):";
    cin>>a>>aper>>b>>count>>c;
    cout<<a<<aper<<b<<count<<c<<endl;
    switch ((a+3)/4-a/4&&(a/400+3)-a/400&&(a+399)/400-a/400)
    {
    case 0:
        if(b==1&&c&&c<=31) cout<<a<<"年"<<b<<"月"<<c<<"日是闰年"<<a<<"年的第"<<c<<"天!"<<endl;
        else
        {
            if(b==2&&c<=29) cout<<a<<"年"<<b<<"月"<<c<<"日是闰年"<<a<<"年的第"<<c+31<<"天!"<<endl;
            else
            {
                if(b==3&&c<=31) cout<<a<<"年"<<b<<"月"<<c<<"日是闰年"<<a<<"年的第"<<c+60<<"天!"<<endl;
                else
                {
                    if(b==4&&c<=30) cout<<a<<"年"<<b<<"月"<<c<<"日是闰年"<<a<<"年的第"<<c+91<<"天!"<<endl;
                    else
                    {
                        if(b==5&&c<=31) cout<<a<<"年"<<b<<"月"<<c<<"日是闰年"<<a<<"年的第"<<c+121<<"天!"<<endl;
                        else
                        {
                            if(b==6&&c<=30) cout<<a<<"年"<<b<<"月"<<c<<"日是闰年"<<a<<"年的第"<<c+152<<"天!"<<endl;
                            else
                            {
                                if(b==7&&c<=31) cout<<a<<"年"<<b<<"月"<<c<<"日是闰年"<<a<<"年的第"<<c+182<<"天!"<<endl;
                                else
                                {
                                    if(b==8&&c<=31) cout<<a<<"年"<<b<<"月"<<c<<"日是闰年"<<a<<"年的第"<<c+213<<"天!"<<endl;
                                    else
                                    {
                                        if(b==9&&c<=30) cout<<a<<"年"<<b<<"月"<<c<<"日是闰年"<<a<<"年的第"<<c+244<<"天!"<<endl;
                                        else
                                        {
                                            if(b==10&&c<=31) cout<<a<<"年"<<b<<"月"<<c<<"日是闰年"<<a<<"年的第"<<c+274<<"天!"<<endl;
                                            else
                                            {
                                                if(b==11&&c<=30) cout<<a<<"年"<<b<<"月"<<c<<"日是闰年"<<a<<"年的第"<<c+305<<"天!"<<endl;
                                                else
                                                {
                                                    if(b==12&&c<=31) cout<<a<<"年"<<b<<"月"<<c<<"日是闰年"<<a<<"年的第"<<c+335<<"天!"<<endl;
                                                    else cout<<"错误日期!"<<endl;
                                                }
                                            }
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
        break;
    case 1:
        if(b==1&&c<=31) cout<<a<<"年"<<b<<"月"<<c<<"日是平年"<<a<<"年的第"<<c<<"天!"<<endl;
        else
        {
            if(b==2&&c<=28) cout<<a<<"年"<<b<<"月"<<c<<"日是平年"<<a<<"年的第"<<c+31<<"天!"<<endl;
            else
            {
                if(b==3&&c<=31) cout<<a<<"年"<<b<<"月"<<c<<"日是平年"<<a<<"年的第"<<c+59<<"天!"<<endl;
                else
                {
                    if(b==4&&c<=30) cout<<a<<"年"<<b<<"月"<<c<<"日是平年"<<a<<"年的第"<<c+90<<"天!"<<endl;
                    else
                    {
                        if(b==5&&c<=31) cout<<a<<"年"<<b<<"月"<<c<<"日是平年"<<a<<"年的第"<<c+120<<"天!"<<endl;
                        else
                        {
                            if(b==6&&c<=30) cout<<a<<"年"<<b<<"月"<<c<<"日是平年"<<a<<"年的第"<<c+151<<"天!"<<endl;
                            else
                            {
                                if(b==7&&c<=31) cout<<a<<"年"<<b<<"月"<<c<<"日是平年"<<a<<"年的第"<<c+181<<"天!"<<endl;
                                else
                                {
                                    if(b==8&&c<=31) cout<<a<<"年"<<b<<"月"<<c<<"日是平年"<<a<<"年的第"<<c+212<<"天!"<<endl;
                                    else
                                    {
                                        if(b==9&&c<=30) cout<<a<<"年"<<b<<"月"<<c<<"日是平年"<<a<<"年的第"<<c+243<<"天!"<<endl;
                                        else
                                        {
                                            if(b==10&&c<=31) cout<<a<<"年"<<b<<"月"<<c<<"日是平年"<<a<<"年的第"<<c+273<<"天!"<<endl;
                                            else
                                            {
                                                if(b==11&&c<=30) cout<<a<<"年"<<b<<"月"<<c<<"日是平年"<<a<<"年的第"<<c+304<<"天!"<<endl;
                                                else
                                                {
                                                    if(b==12&&c<=31) cout<<a<<"年"<<b<<"月"<<c<<"日是平年"<<a<<"年的第"<<c+334<<"天!"<<endl;
                                                    else cout<<"错误日期!"<<endl;
                                                }
                                            }
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
        break;
    }
    return 0;
}

有兴趣的帮忙看下，这个码还有很多错误的运算，但是我数学不是很厉害，公式实在不知道杂用了，高手帮忙指点下。
能够帮忙简化和校正，感激不尽啊。

天。。。你这代码风格。。。太有爱了。。。
建议把每个月天数保存在一个数组里面，大小设置为12，比如 int days[12]，里面初始化为非闰年的每月的天数，如果是闰年那么修改day[1]的天数为29即可，可以看着好很多。。。

滚动滑轮 挺有动感

    简化后的程序:
#include "iostream.h"
int main()
{
    int a,b,c;
    char aper,count;
    cout<<"输入日期(如:2005-2-8):";
    cin>>a>>aper>>b>>count>>c;
    cout<<a<<aper<<b<<count<<c<<endl;

    int key;
    if(a%400==0||a%4==0&&a%100!=0)
        key=1;
    else
        key=0;
    switch (key)
    {
    case 1:
        cout<<a<<"年是闰年"<<endl;
        break;
    case 0:
        cout<<a<<"年是平年"<<endl;
        break;
    }

    int sum=31+28+key+31+30+31+30+31+30+30+31+30+31+c;
    switch(b)
    {
    case 1:
        sum-=31;
    case 2:
        sum-=(key+28);
    case 3:
        sum-=31;
    case 4:
        sum-=30;
    case 5:
        sum-=31;
    case 6:
        sum-=30;
    case 7:
        sum-=31;
    case 8:
        sum-=30;
    case 9:
        sum-=30;
    case 10:
        sum-=31;
    case 11:
        sum-=30;
    case 12:
        sum-=31;
    }
    cout<<a<<aper<<b<<count<<c<<"是"<<a<<"年的第"<<sum<<"天"<<endl;
    return 0;
}

楼猪还有耐心

if(a%400==0||a%4==0&&a%100!=0)
这个高手，这个可以解释解释么~~~你的码没有备注，我看得不是很懂，刚学没几天呢~~~

那个是闰年和平年的判断，能被400整除或能被4整除且不能被100整除的就是闰年，闰年和平年的区别不就是二月的不同嘛，就用key表示1或0,在28上加key表示二月的天数。
switch语句也相当于是个条件语句，没有break的时候找到相等的就一直向下执行完；

呵呵，看懂了，谢谢啊，谢谢了，%是整除，我以为是除了之后可以有小数，如10%3=3.33333...看来我误会了，呵呵。只知道10/3=3.呵呵
十分感谢！

再问个问题~~~  -=是什么意思？sum-=31;   解释下，这个代码我就全懂咯。

呵呵，看懂了，谢谢啊，谢谢了，%是整除，我以为是除了之后可以有小数，如10%3=3.33333...看来我误会了，呵呵。只知道10/3=3.呵呵
十分感谢！

再问个问题~~~  -=是什么意思？sum-=31;   解释下，这个代码我就全懂咯。

再帮忙解释解释，呵呵，感激不尽啊，嘿嘿。