为什么我写 的好好的C代码 复制到QQ群论坛就会自动改变呢

main()
{
    int year;
    for (year=2000;year<=2500;year++)
    {
        if (year%4==0)
        {
            if (year%100!=0)printf("%d ",year);
            else
            {
                if (year%400==0)printf("%d ",year);
            }
        }
    }
    getch();
}

main()
{
    int year;
    for (year=2000;year<=2500;year++)
    {
        if (year%4==0)
        {
            if (year0!=0)printf("%d ",year);
            else
            {
                if (year@0==0)printf("%d ",year);
            }
        }
    }
    getch();
}