Cod sursa(job #809838)

Utilizator ahmed.abdraboahmed.abdrabo ahmed.abdrabo Data 9 noiembrie 2012 05:43:54
Problema Invers modular Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.71 kb
#include <cstdio>
using namespace std;

inline int next_int() {
	int d;
	scanf("%d", &d);
	return d;
}

long long fi(long long n) {
	long long result = n;
	for (long long i = 2; i * i <= n; i++) {
		if (n % i == 0)
			result -= result / i;
		while (n % i == 0)
			n /= i;
	}
	if (n > 1)
		result -= result / n;
	return result;
}

inline long long pow(long long a, long long b, long long mod) {
	long long ans = 1;
	while (b) {
		if (b & 1) {
			ans = (ans * a) % mod;
		}
		a = (a * a) % mod;
		b >>= 1;
	}
	return ans;
}

int main() {
	freopen("inversmodular.in", "r", stdin);
	freopen("inversmodular.out", "w", stdout);
	long long n = next_int();
	long long p = next_int();
	printf("%lld\n", pow(n, fi(p) - 1, p));
	return 0;
}