Submission #599791

#	Time	Username	Problem	Language	Result	Execution time	Memory
599791		flappybird	Amusement Park (CEOI19_amusementpark)	C++17	100 / 100	1468 ms	3500 KiB

amusementpark

#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx,avx2,fma")
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
#define MAX 20
#define MAXS 18
#define INF 1000000000000000001
#define bb ' '
#define ln '\n'
#define Ln '\n'
#define smin(a, x) (a)=(min((a), (x)))
ll dp[303030];
int ban[MAX];
int mul[303030];
const int mod = 998244353;
signed main() {
	ios::sync_with_stdio(false), cin.tie(0);
	int N, M;
	cin >> N >> M;
	int i, j, a, b;
	for (i = 1; i <= M; i++) {
		cin >> a >> b;
		ban[--a] |= 1 << --b;
		ban[b] |= 1 << a;
	}
	int K = 1 << N;
	dp[0] = 1;
	for (j = 0; j < K; j++) {
		int c = 0;
		for (int k = 0; k < N; k++) if ((j & (1 << k)) && (ban[k] & j)) c = 1;
		if (c) continue;
		mul[j] = -1;
		for (int k = 0; k < N; k++) if (j & (1 << k)) mul[j] *= -1;
	}
	for (i = 0; i < K; i++) { for (j = i; j; (--j) &= i) { dp[i] += dp[i ^ j] * (ll)mul[j], dp[i] %= mod; } }
	if (dp[K - 1] < 0ll) dp[K - 1] += mod;
	dp[K - 1] *= M;
	dp[K - 1] %= mod;
	if (dp[K - 1] % 2) dp[K - 1] += mod;
	dp[K - 1] /= 2;
	cout << dp[K - 1] << ln;
}

• Subtask 1: 7 / 7
• Subtask 2: 12 / 12
• Subtask 3: 23 / 23
• Subtask 4: 21 / 21
• Subtask 5: 37 / 37