Cod sursa(job #1902596)
Utilizator | Data | 4 martie 2017 18:02:48 | |
---|---|---|---|
Problema | Invers modular | Scor | 40 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.42 kb |
#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("inversmodular.in");
ofstream fout("inversmodular.out");
int a, n;
int lgpow(int x, int p)
{
int r=1;
for(int i=0;(1<<i)<=p;i++)
{
if((1<<i)&p)
{
r=(1ll*x*r)%n;
}
x=(1ll*x*x)%n;
}
return r;
}
int main()
{
fin>>a>>n;
fout<<lgpow(a,n-2);
return 0;
}