程序代码：

#include<stdio.h>
int zihanshu(int n1,int n2)
{
    int t,a,b;
    if(n1<n2)
    {
        t=n1;
        n1=n2;
        n2=t;
    }
    a=n1;
    b=n2;
    while(b)
    {
        t=a%b;
        a=b;
        b=t;
    }
    return(a);
}
void main()
{
    printf("%d",zihanshu(8,12));
}