Submission #319853

#	Time	Username	Problem	Language	Result	Execution time	Memory
319853		NachoLibre	Tents (JOI18_tents)	C++14	0 / 100	1 ms	396 KiB

tents

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

const int mod = 1e9 + 7;
const int N = 3003, M = N;
int n, m, dp[N][M];

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> n >> m;
	for(int i = 1; i <= n; ++i) {
		for(int j = 1; j <= m; ++j) {
			if(i == 1 && j == 1) {
				dp[i][j] = 5;
			} else if(i == 1) {
				dp[i][j] = 1ll + j * 4 + j * (j - 1) / 2;
			} else if(j == 1) {
				dp[i][j] = 1ll + i * 4 + i * (i - 1) / 2;
			} else if(j == 2 && i == 2) {
				dp[i][j] = 53;
			} else if(j == 2) {
				dp[i][j] = (1ll + dp[i - 1][j] + 8ll * dp[i - 1][j - 1] + 2ll * dp[i - 2][j - 1]) % mod;
			} else if(i == 2) {
				dp[i][j] = (1ll + dp[i][j - 1] + 8ll * dp[i - 1][j - 1] + 2ll * dp[i - 1][j - 2]) % mod;
			} else {
				dp[i][j] = (1ll * dp[i - 1][j] + 4ll * j * dp[i - 1][j - 1] + 1ll * j * (i - 1) * dp[i - 2][j - 1] + 1ll * j * (j - 1) / 2 * dp[i - 1][j - 2]) % mod;
			}
		}
	}
	cout << (dp[n][m] + mod - 1) % mod;
	return 0;
}

• Subtask 1: 0 / 48
• Subtask 2: 0 / 52