Cod sursa(job #2900817)
Utilizator | Data | 12 mai 2022 10:53:53 | |
---|---|---|---|
Problema | Invers modular | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.66 kb |
#include <bits/stdc++.h>
using namespace std;
long long x,mod;
long long lgput(long long a, long long b)
{
long long r=1;
while(b>0)
{
if(b&1)
r=(r*a)%mod;
a=(a*a)%mod;
b>>=1;
}
return r;
}
ifstream fin("inversmodular.in");
ofstream fout("inversmodular.out");
int phi(int n)
{
int r=n,d=2;
while(n>1)
{
if(n%d==0)
{
r=r/d*(d-1);
while(n%d==0)n/=d;
}
d++;
if(d*d>n)
d=n;
}
return r;
}
signed main()
{
fin>>x>>mod;
fout<<lgput(x,phi(mod)-1)<<'\n';
return 0;
}