#include<stdio.h>
#include<windows.h>
int main()
{
printf("hello world!");
Sleep(2000);
return 0;
}

#include<stdio.h>
#include<windows.h>
int main()
{
int a,i;
printf("read a : ");
scanf("%d",&a);
for(i=1;i<=a;i++)
{
if (a%i==0) printf("%d ",i);
}
Sleep(2000);
return 0;
}

#include<stdio.h>
#include<Windows.h>
#include<math.h>
int main()
{
int a,b,c;
double i,s1,s2;
printf("此程序求二次方程“ax2+bx+c=0”的解\n");
printf("输入a\n");
scanf("%d",&a);
printf("输入b\n");
scanf("%d",&b);
printf("输入c\n");
scanf("%d",&c);
i=b*b-4*a*c;
if(i<0)
{
printf("无实根");
Sleep(5000);
return 0;
}
s1=((-1)*b+sqrt(i))/2/a;
s2=((-1)*b-sqrt(i))/2/a;
printf("x1=%f\n",s1);
printf("x2=%f\n",s2);
Sleep(5000);
return 0;
}

#include<stdio.h>
#include<windows.h>
int main()
{
int a,b,c,m,n;
printf("a=");
scanf("%d",&a);
printf("b=");
scanf("%d",&b);
m=a;
n=b;
c=a%b;
while(c>0)
{
a=b;
b=c;
c=a%b;
}
printf("最大公因数%d\n",b);
c=m*n/b;
printf("最小公倍数%d\n",c);
Sleep(5000);
return 0;
}