Pagini recente » Cod sursa (job #569667) | Cod sursa (job #514554) | Cod sursa (job #159294) | Cod sursa (job #417569) | Cod sursa (job #2299433)
#include <iostream>
using namespace std;
int Phi (int n ) {
int val, p ;
p = 2 ;
val = n ;
while (n > 0 && p * p <= n ) {
if (n % p == 0 ) {
val = val * ( p - 1 ) / p ;
while (n % p == 0 )
n /= p ;
}
p++;
}
if (n > 1 )
val = val * ( n - 1 ) / n ; /// a mai ramas un nr. prim
return val ;
}
int Putere (int a, int n, int mod ) { /// a ^ n
int prod ;
prod = 1 ;
while (n > 0 ) {
if (n % 2 == 1 ) {
prod = ( (prod % mod) * (a % mod) ) % mod ;
n--;
} else {
a = (a % mod) * (a % mod) % mod ;
n /= 2 ;
}
}
return prod ;
}
int main() {
FILE *fin, *fout ;
fin = fopen ("inversmodular.in", "r" ) ;
fout = fopen ("inversmodular.out", "w" ) ;
int n, a ;
fscanf (fin, "%d%d", &a, &n) ;
fprintf (fout, "%d ", Putere(a, Phi(n)-1, n) ) ;
return 0;
}