> #include<stdio.h>
> typedef long long ll;
> ll gcd(ll a,ll b,ll &x,ll &y)
> {
> 	if(b==0)
> 	{
> 		x=1;
> 		y=0;
> 		return a;
> 	}
> 	ll d=gcd(b,a%b,x,y);
> 	ll t=x;
> 	x=y;
> 	y=t-a/b*y;
> 	return d;
> }
> int main()
> {
> 	ll A,B,C,K;
> 	ll x,y;
> 	while(scanf("%lld%lld%lld%lld",&A,&B,&C,&K)&&(A||B||C||K))
> 	{
> 		ll c=B-A;
> 	    ll a=C;
> 	    ll b=(ll)1<<K;
> 	    ll d=gcd(a,b,x,y);
> 		if(c%d)
> 		{
> 		printf("FOREVER\n");
> 		continue;
> 		} 
> 		ll s=b/d;
> 		ll min=(x*c/d%s+s) %s;
> 		printf("%lld\n",min);
> 	}
> 	return 0;
> }

• Re:0M 水过~~欧几里得模板水题 (2) 1617186984 2017-11-30 21:02:55