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134<snippet>
<content><{return (long long)(((__int128_t)x*(__int128_t)x+(__int128_t)c)%n);};
for(c=1;c<n;c++){
long long x=1,y=1,ys=1;
__int128_t q=1;
long long g=1;
constexpr int m=128;
for(int r=1;g==1;r<<=1){
x=y;
for(int i=0;i<r;i++) y=f(y);
for(int k=0;g==1&&k<r;k+=m){
ys=y;
for(int i=0;i<m&&i<r-k;i++){
q*=abs(x-(y=f(y)));
q%=n;
}
g=gcd(n,(long long)q);
}
}
if(g==n){
do{
g=gcd(n,abs(x-(ys=f(ys))));
}while(g==1);
}
if(g!=n) return g;
}
}
vector<long long> factorize_init(long long n){
if(n<=1) return {};
long long p=pollard_rho(n);
if(p==n) return {n};
auto l=factorize_init(p);
auto r=factorize_init(n/p);
copy(r.begin(),r.end(),back_inserter(l));
return l;
}
vector<long long> factorize(long long n){
vector<long long> res=factorize_init(n);
sort(res.begin(),res.end());
return res;
}
vector<pair<long long,long long>> factorize_prime(long long n){
vector<long long> res=factorize(n);
vector<pair<long long,long long>> ret;
for(int i=0;i<res.size();i++){
if(i==0||res[i]!=res[i-1]) ret.push_back({res[i],1});
else ret[ret.size()-1].second++;
}
return ret;
}
vector<long long> divisor(long long n){
vector<pair<long long,long long>> v=factorize_prime(n);
vector<long long> ret;
auto f=[&](auto rc,int i,long long x)->void{
if(i==(int)v.size()){
ret.push_back(x);
return;
}
for(int j=0;j<=v[i].second;j++){
rc(rc,i+1,x);
x*=v[i].first;
}
};
f(f,0,1);
sort(ret.begin(),ret.end());
return ret;
}
};
using namespace fast_factrize;
/*
*use:: vector<long long> d = divisor(n); to get all divisors(not only prime)
*use:: vector<pii> f = factorize_prime(n) to get prime factorisations and so prime divisors
*i think O(n^(1/4)) which means upto 1e30 for t=1? and t=1000 if n<=1e18
n<=1e18 with t=1000 tested: https://atcoder.jp/contests/abc293/submissions/39622575 =>438 ms
*/
]]></content>
<!-- Optional: Set a tabTrigger to define how to trigger the snippet -->
<tabTrigger>pollard</tabTrigger>
<!-- Optional: Set a scope to limit where the snippet will trigger -->
<scope>source.c++</scope>
</snippet>