BZOJ 3667 Miller_Rabin

模板题

注意Pollard_Rho()的写法

第一次比较应该是 a-0步，b-1步

#include <cstdio>
#include <cstdlib>
#include <algorithm>

using std::max;

typedef long long ll;

int T;
ll N;

ll Pri[10]={2LL, 3LL, 5LL, 7LL, 11LL, 13LL, 17LL, 19LL, 23LL, 29LL};

ll Rand(){
	return rand()*1034567890LL+(ll)(rand());
}

ll Rand(ll l, ll r){
	return Rand()%(r-l+1LL)+l;
}

ll abs(ll a){
	return (a>0LL)?a:(-a);
}

ll gcd(ll a, ll b){
	return (b==0LL)?a:gcd(b, a%b);
}

ll MOD;

ll sr;
ll sum(ll a, ll b){
	sr=a+b;
	if(sr>=MOD)	sr-=MOD;
	return sr;
}

ll mul(ll a, ll b){
	ll k=(ll)((1.0L*a*b)/(1.0L*MOD));
	ll r=a*b-k*MOD;
	if(r<0)	r+=MOD;
	return r;
}

ll pow(ll a, ll k){
	ll ret=1LL, t=a;
	while(k>0LL){
		if(k&1LL)	ret=mul(ret, t);
		t=mul(t, t);
		k>>=1;
	}
	return ret;
}

bool Miller_Rabin(ll n){
	if(n<2LL)	return false;
	if(n==2LL)	return true;
	if((n&1LL)==0LL)	return false;
	MOD=n;
	int k=0;
	ll m=n-1, a;
	while((m&1LL)==0LL)	{++k;m>>=1;}
	bool ret=true;
	for(int i=0, j;i<10 && ret;++i){
		if(Pri[i]>=n)	break;
		a=pow(Pri[i], m);
		if(a==1LL)	continue;
		for(j=0;j<k;++j){
			if(a==n-1LL)	break;
			a=mul(a, a);
		}
		if(j==k)	ret=false;
	}
	return ret;
}

ll Pollard_Rho(ll c, ll n){
	MOD=n;
	ll a=Rand(1LL, n-1LL), b=sum(mul(a, a), c), d;
	while(a!=b){
		d=gcd(abs(a-b), n);
		if(d>1LL)	return d;
		a=sum(mul(a, a), c);
		b=sum(mul(b, b), c);b=sum(mul(b, b), c);
	}
	return n;
}

ll Rho(ll n){
	if(Miller_Rabin(n))	return n;
	ll t=n;
	while(t==n)	t=Pollard_Rho(Rand(1LL, n-1LL), n);
	return max(Rho(t), Rho(n/t));
}

int main(){
	
	srand(1075757);
	
	scanf("%d", &T);
	
	while(T--){
		
		scanf("%lld", &N);
		
		if(Miller_Rabin(N))	puts("Prime");
		else	printf("%lld\n", Rho(N));
		
	}	
	
	return 0;
}