Cod sursa(job #229758)
| Utilizator | Data | 11 decembrie 2008 13:28:10 | |
|---|---|---|---|
| Problema | Invers modular | Scor | 60 |
| Compilator | cpp | Status | done |
| Runda | Arhiva educationala | Marime | 0.47 kb |
using namespace std;
#include <cstdio>
#define ll long long
#define IN "inversmodular.in"
#define OUT "inversmodular.out"
ll N,A;
ll pow(int x,int p)
{
ll a;
return (!p?1:(p&1?x * pow(x,p-1):(a = pow(x,p>>1))*a) ) % N;
}
int main()
{
freopen(IN,"r",stdin);
freopen(OUT,"w",stdout);
scanf("%lld%lld",&A,&N);
ll rez1 = pow(A,N-2);
if( rez1 * A % N == 1)
printf("%lld\n",rez1 % N);
else
printf("%lld\n",(rez1 * A) % N * A);
return 0;
}
