【POJ1811】Prime Test

【题目大意】

若n是素数，输出“Prime”，否则输出n的最小素因子，（n<=2^54）

【题解】

和bzoj3667差不多，知识这道题没那么坑。

直接上Pollord_Rho和Rabin_Miller就行了。

 /*************
   POJ 1811
   by chty
   2016.11.7
 *************/
 #include<iostream>
 #include<cstdio>
 #include<cstdlib>
 #include<cstring>
 #include<ctime>
 #include<cmath>
 #include<algorithm>
 using namespace std;
 typedef long long ll;
 const ll INF=1000000000000000000LL;
 const ll prime[]={,,,,,,,,};
 ll T,minn;
 inline ll read()
 {
     ll x=,f=;  char ch=getchar();
     while(!isdigit(ch))  {if(ch=='-')  f=-;  ch=getchar();}
     while(isdigit(ch))  {x=x*+ch-'';  ch=getchar();}
     return x*f;
 }
 ll gcd(ll a,ll b) {return !b?a:gcd(b,a%b);}
 ll mul(ll x,ll y,ll mod) {return ((x*y-(ll)(((long double)x*y+0.5)/mod)*mod)%mod+mod)%mod;}
 ll fast(ll a,ll b,ll mod) {ll sum=;for(;b;b>>=,a=mul(a,a,mod))if(b&)sum=mul(sum,a,mod);return sum;}
 bool Rabin_Miller(ll p,ll a)
 {
     if(p==)  return ;
     if(!(p&)||p==)  return ;
     ll d=p-;
     while(!(d&))  d>>=;
     ll m=fast(a,d,p);
     if(m==)  return ;
     for(;d<p;d<<=,m=mul(m,m,p)) if(m==p-)  return ;
     return ;
 }
 bool isprime(ll x)
 {
     for(ll i=;i<;i++)
     {
         if(prime[i]==x)  return ;
         if(!Rabin_Miller(x,prime[i]))  return ;
     }
     return ;
 }
 void Pollord_Rho(ll x)
 {
     if(isprime(x))  {minn=min(minn,x);  return;}
     ll c=;
     while()
     {
         ll x1(),x2(),i(),k();
         while()
         {
             x1=(mul(x1,x1,x)+c)%x;
             ll d=gcd(x1>x2?x1-x2:x2-x1,x);
             if(d>&&d<x)
             {
                 Pollord_Rho(d);
                 Pollord_Rho(x/d);
                 return;
             }
             if(x1==x2)  break;
             if(++i==k)  x2=x1,k<<=;
         }
         c++;
     }
 }
 void solve(ll x)
 {
     if(isprime(x))  {puts("Prime"); return;}
     minn=INF;
     Pollord_Rho(x);
     printf("%lld\n",minn);
 }
 int main()
 {
     freopen("cin.in","r",stdin);
     freopen("cout.out","w",stdout);
     T=read();
     while(T--){ll x=read();solve(x);}
     return ;
 }