poj1811 Prime Test

http://poj.org/problem?id=1811

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <ctime>
using namespace std;
typedef __int64 LL;
const int times = 10;
LL minf, n;

LL random(LL n){
    return (double)rand() / RAND_MAX * n + 0.5;
}

LL multi(LL a, LL b, LL mod){
    a %= mod, b %= mod;
    LL ans = 0;
    while(b){
        if(b & 1) ans += a, ans %= mod;
        b >>= 1;
        a <<= 1;
        a %= mod;
    }
    return ans;
}

LL power(LL a, LL p, LL mod){
    a %= mod;
    LL ans = 1;
    while(p){
        if(p & 1) ans = multi(ans, a, mod);
        p >>= 1;
        a = multi(a, a, mod);
    }
    return ans;
}

LL gcd(LL a, LL b){
    if(!b) return a;
    return gcd(b, a % b);
}

bool witness(LL a, LL n){
    LL u = n - 1;
    while(!(u & 1)) u >>= 1;
    LL t = power(a, u, n);
    while(u != n - 1 && t != 1 && t != n - 1){
        t = multi(t, t, n);
        u <<= 1;
    }
    return t == n - 1 || u & 1;
}

bool miller_rabin(LL n){
    if(n == 2) return 1;
    if(n < 2 || !(n & 1)) return 0;
    //test for odd numbers larger than 2
    for(int i = 0; i < times; i++){
        LL p = random(n - 2) + 1;
        if(!witness(p, n)) return 0;
    }
    return 1;
}

LL pollard_rho(LL n, LL t){
    LL x = random(n - 2) + 1;
    LL y = x;
    LL i = 1, k = 2, d;
    while(1){
        ++i;
        x = (multi(x, x, n) + t) % 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;
        }
    }
}

void fact(LL n, LL t){
    if(n == 1) return;
    if(miller_rabin(n)){
        minf = min(minf, n);
        return;
    }
    LL p = n;
    while(p >= n) p = pollard_rho(p, t--);
    fact(p, t);
    fact(n / p, t);
}

void solve(){
    //if n is prime
    if(miller_rabin(n)){
        puts("Prime");
        return;
    }
    //try to factorize n
    //initialize the minimum non trival factor of n
    minf = n;
    fact(n, 122);
    printf("%I64d
", minf);
}

int main(){
    //freopen("in.txt", "r", stdin);
    int T;
    scanf("%d", &T);
    while(T--) scanf("%I64d", &n), solve();
    return 0;
}