【HDU-6608】Fansblog

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

ll multi(ll a,ll b,ll c) {
	ll ans = 0; a %= c;
	while (b) {
		if (b & 1) ans = (ans + a) % c;
		b >>= 1; a = (a + a) % c;
	}
	return ans;
}

ll modular_exp(ll a,ll m,ll n) {
	if (m == 0) return 1;
	if (m == 1) return a%n;
	ll w = modular_exp(a, m/2, n); w = multi(w, w, n);
	if (m & 1) w =multi(w, a, n);
	return w;
}

bool Miller_Rabin(ll n) {
	srand(time(NULL));
	if (n == 2) return true;
	for (int i = 0; i < 10; ++i) {
		int a = rand() % (n-2) + 2;
		if (modular_exp(a, n, n) != a) return false;
	}
	return true;
}

void extend_gcd(ll a,ll b,ll &x,ll &y) {
	if (b == 0) {
		x = 1; y = 0; return;
	}
	extend_gcd(b, a%b, y, x);
	y -= (a/b) * x;
}

ll inv(ll a,ll b) {
	ll x, y; extend_gcd(a, b, x, y);
	return (x + b) % b;
}

int main() {
	int T; cin >> T;
	while (T--) {
		ll P; scanf("%lld",&P);
		ll Q = P - 1, ans = P - 1;
		while (!Miller_Rabin(Q)) Q--;
		for (ll i = Q + 1; i <= P - 1; ++i) {
			ll tmp = inv(i, P);
			ans = multi(ans, tmp, P);
		}
		printf("%lld\n",ans);
	}
	return 0;
}