【数论】POJ_2115_C Looooops

http://blog.csdn.net/non_cease/article/details/7364092

这篇博客写的炒！鸡！好！，喜翻～

解题思路看这篇博客

http://blog.csdn.net/lyy289065406/article/details/6648546

好了，没我的什么事了～

#include <stdio.h>#include <math.h>#define ll long longll x,y;ll int Extended_Euclid(ll a,ll b){    if(b==0)    {        x=1;        y=0;        return a;    }    ll m=Extended_Euclid(b,a%b);    ll temp=x;    x=y;    y=temp-a/b*y;    return m;}int main(){    ll A,B,C,K;    while(~scanf("%lld%lld%lld%lld",&A,&B,&C,&K)&&!(A==0&&B==0&&C==0&&K==0))    {        ll a=C;        ll b=(ll)1<<K;        ll n=B-A;        ll d=Extended_Euclid(a,b);        if(n%d)        {            printf("FOREVER\n");            continue;        }        ll t=b/d;        ll x0=((x*n/d)%t+t)%t;        printf("%lld\n",x0);    }}