Submission #72578

#	Time	Username	Problem	Language	Result	Execution time	Memory
72578		Abelyan	Tents (JOI18_tents)	C++17	100 / 100	137 ms	71364 KiB

tents

#include <iostream>
#include <algorithm>
#include <vector>
#include <cstdio>
#include <queue>
#include <map>
#include <set>
#include <cmath>
using namespace std;

typedef long long ll;
const int N = 3006;
const ll MOD = 1000000007;
ll dp[N][N];


int main() {
	ios_base::sync_with_stdio(false);
	int n,m;
	cin >> n >> m;
	for (int i = 1; i <= max(n,m); i++) {
		dp[0][i]=dp[i][0] = 1;
		dp[1][i]=dp[i][1] = i*(i - 1) / 2 + 4 * i + 1;
	}
	for (ll i = 2; i <= n; i++) {
		for (ll j = 2; j <= m; j++) {
			dp[i][j] = (i * 4 * dp[i - 1][j - 1] + i*(j - 1)*dp[i - 1][j - 2] + dp[i][j - 1] + (i*(i - 1) / 2) * dp[i - 2][j - 1]) % MOD;
		}
	}
	cout << dp[n][m]-1 << endl;
	system("pause");
	return 0;
}

Compilation message (stderr)

tents.cpp: In function 'int main()':
tents.cpp:31:8: warning: ignoring return value of 'int system(const char*)', declared with attribute warn_unused_result [-Wunused-result]
  system("pause");
  ~~~~~~^~~~~~~~~

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