Submission #9821

#	Time	Username	Problem	Language	Result	Execution time	Memory
9821		veckal	Phibonacci (kriii2_P)	C++14	4 / 4	0 ms	1088 KiB

P

#include<cstdio>
#include<utility>
using namespace std;
typedef long long ll;
const int MOD = 1000000000 + 7;

ll n, k;

struct Matrix {
	ll mat[2][2];
	Matrix() {
		mat[0][0]=mat[0][1]=mat[1][0]=mat[1][1]=0;
	}
};

Matrix operator *(Matrix& A, Matrix& B) {
	Matrix ret;
	for (int i=0; i<2; ++i)
		for (int j=0; j<2; ++j)
			for (int k=0; k<2; ++k)
				ret.mat[i][j] = (ret.mat[i][j] + A.mat[i][k] * B.mat[k][j])%MOD;
	return ret;
}

Matrix power(Matrix base, ll exp) {
	Matrix ret;
	ret.mat[0][0] = ret.mat[1][1] = 1;
	while(exp) {
		if (exp&1) ret = ret * base;
		base = base * base;
		exp >>= 1;
	}
	return ret;
}

pair<long long, long long> extended_gcd(long long a, long long b) {
	if (b == 0) return make_pair(1, 0);
	pair<long long, long long> t = extended_gcd(b, a % b);
	return make_pair(t.second, t.first - t.second * (a / b));
}

long long modinverse(long long a, long long m) {
	return (extended_gcd(a, m).first % m + m) % m;
}

ll power(ll base, ll exp) {
	if (exp < 0) return 0;
	ll ret = 1;
	while(exp) {
		if (exp&1) ret = (ret*base)%MOD;
		base = (base*base)%MOD;
		exp >>= 1;
	}
	return ret;
}

int main() {
	scanf("%lld%lld", &n, &k);
	Matrix base;
	base.mat[0][0] = base.mat[0][1] = base.mat[1][0] = 1;
	Matrix a_k = power(base, k);
	Matrix a_nk = power(a_k, n);
	ll f_nk = a_nk.mat[0][1];
	ll f_nk_1 = a_nk.mat[1][1];
	ll f_k = a_k.mat[0][1];
	ll f_k_1 = a_k.mat[1][1];
	ll ans1, ans2;
	if (f_k == 0) ans1 = n * power(f_k_1, n-1) % MOD;
	else ans1 = f_nk * modinverse(f_k, MOD) % MOD;
	ans2 = (f_nk_1 - f_k_1 * ans1 % MOD + MOD) % MOD;
	printf("%lld %lld\n", ans1, ans2);
	return 0;
}

• Subtask 1: 1 / 1
• Subtask 2: 3 / 3