gcd

long long gcd(long long x,long long y)
{
    long long a;
    if(x<y) a=x,x=y,y=a;
    while(y!=0)
    {
        a=x%y;
        x=y;
        y=a;
    }
    return x;

转载于:https://www.cnblogs.com/superxuezhazha/p/5539846.html