FFT质数打表程序

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
void sol(ll x){
    int y=0;
    for(ll i=2;i*i<=x;++i)
        if(x%i==0){
            int j=0;
            for(;x%i==0;x/=i)++j;
            if(y++)cout<<"*";
            cout<<i;
            if(j!=1)cout<<"^"<<j;
        }
    if(x!=1){
        if(y)cout<<"*";
        cout<<x;
    }
    cout<<endl;
}
bool jud(ll x){
    for(ll i=2;i*i<=x;++i)
        if(x%i==0)return 0;
    return 1;
}
ll wop(ll s,ll n,ll p){
	ll t=1;
	for(;n;n>>=1){
		if(n&1)t=t*s%p;
		if(n>1)s=s*s%p;
	}
	return t;
}
ll phi(ll x){
	ll s=x;
	for(ll i=2;i*i<=x;++i)
		if(x%i==0){
			while(x%i==0)x/=i;
			s=s/i*(i-1);
		}
	if(x!=1)s=s/x*(x-1);
	return s;
}
ll gen(ll p){
	static ll c[16];
	ll s=phi(p),x=s;
	int k=0;
	for(ll i=2;i*i<=x;++i)
		if(x%i==0){
			while(x%i==0)x/=i;
			c[k++]=i;
		}
	if(x!=1)c[k++]=x;
	for(ll i=2;;++i){
		int j=0;
		while(j!=k&&wop(i,s/c[j],p)!=1)
			++j;
		if(j==k)return i;
	}
}
void out(ll p){
    int j=__builtin_ctzll(p-1);
    cout<<setw(8)<<p;
    cout<<setw(4)<<gen(p);
    cout<<"  2^"<<j;
    cout<<" * "<<setw(5)<<(p-1>>j);
    cout<<endl;
}
int main(){
	for(ll i=1;;++i){
		ll j=(i<<20)+1;
		if(j>2e9)break;
		if(jud(j))out(j);
	}
}
posted @ 2016-06-12 18:59  f321dd  阅读(252)  评论(0编辑  收藏  举报