Cod sursa(job #2433768)
Utilizator | Popescu Stefan stefan.popescu | Data | 28 iunie 2019 22:17:14 |
---|---|---|---|
Problema | Invers modular | Scor | 0 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.61 kb |
#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;
ifstream in ("inversmodular.in");
ofstream out("inversmodular.out");
int a, n, mod, i, diviz=1;
int explog(int x1, int n1)
{
int p=1;
int x=x1;
while(n1>0)
{
if(n1%2==1)
{
p=p*x%mod;
n--;
}
x=x*x%mod;
n1/=2;
}
return p;
}
int main()
{
in>>a>>n;
mod=n;
for(i=2; i*i<=n; i++)
{
if(n%i==0) diviz+=2;
}
if((i-1)*(i-1)==n) diviz--;
diviz=n-diviz;
out<<explog(a, diviz-1);
return 0;
}