int gcd(int a,int b)
{
    while(a!=b)
    {
       if(a>b)
           a-=b;
       else
           b-=a;
    }
    return a;
}

int gcd(int a,int b)
{
    if(b==0)
       return a;
    else
       return gcd(b,a%b);
}

int gcd(int a,int b)
{
    int r;
    while(b!=0)
    {
       r=a%b;
       a=b;
       b=r;
    }
    return a;
}

//穷举法求最小公倍数  
for (i= a; ; i++ )  
    if ( i % a == 0 && i % b ==0 )     break;  
    printf("The least common multiple:%d\n", i )