大數的質數檢驗以及求最小質因子

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <time.h>
#include <stdlib.h>
using namespace std;
typedef long long ll;
ll random(ll n)
{
    return ((double)rand()/RAND_MAX*n+0.5);
}
ll powmuilt(ll a,ll b,ll mod)
{
    ll ans=0;
    while(b)
    {
        if(b & 1)
        {
            ans = (ans+a)%mod;
        }
        b>>=1;
        a= (2*a)%mod;
    }
    return ans;
}
ll powexp(ll a, ll b, ll mod)
{
    ll ans=1;
    while(b)
    {
       if(b & 1) ans = powmuilt(ans,a,mod);
       b>>=1;
       a = powmuilt(a,a,mod);
    }
    return ans;
}

bool wintness(ll a, ll n)
{
    ll d=n-1;
    while (!(d & 1)) d>>=1;
    ll t=powexp(a,d,n);
    while( d!=n-1 && t!=1 && t!=n-1)
    {
        t = powmuilt(t,t,n);
        d<<=1;
    }
    return t==n-1|| d&1 ;
}
bool miller_rabin(ll n)
{
   if(n==2) return 1;
   if(n<2 || !(n&1)) return 0;
   for(int i=1;i<=10;++i)
   {
       ll a=random(n-2)+1;
       if(!wintness(a,n)) return 0;
   }
   return 1;
}

ll gcd(ll a ,ll b)
{
    if(b==0) return  a;
    return gcd(b,a%b);
}
ll pollard_rho(ll n, ll c)
{
    ll x,y,d,i=1,k=2;
    x=random(n-2)+1;
    y=x;
    while(1)
    {
        ++i;
        x=(powmuilt(x,x,n)+c)%n;
        d=gcd(y-x,n);
        if(1<d &&d<n) return d;
        if(x==y) return n;
        if(i==k)
        {
            y=x; k<<=1;
        }
    }
}
ll mi;
void ffind(ll n,ll c)
{
    if(n==1) return;
    if(miller_rabin(n))
    {
        mi=min(mi,n);
        return ;
    }
    ll p=n;
    while(p>=n) p=pollard_rho(p,c--);
    ffind(p,c);
    ffind(n/p,c);
}

int main()
{
    int T;
    scanf("%d",&T);
    while(T--)
    {
        ll n;
        scanf("%lld",&n);
        mi =n;
        if(miller_rabin(n))
        {
            printf("Prime\n");
        }
        else
        {
            ffind(n,12312);
            printf("%lld\n",mi);
        }
    }
    return 0;
}