Submission #900516

#	Time	Username	Problem	Language	Result	Execution time	Memory
900516		guechotjrhh	Tents (JOI18_tents)	C++14	100 / 100	69 ms	492 KiB

tents

#include<iostream>
#include<vector>
using namespace std;
#define ll long long
int mod = 1e9 + 7;

int func(int n, int m) {
	vector<ll> dp1(m+1, 0), dp2(m+1, 0), dp3(m+1, 0);
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= m; j++) {
			dp3[j] = dp2[j]; //empty
			dp3[j] += (1 + dp2[j-1]) * 4 * j; //one, not connected
			if (j > 1) dp3[j] += (1 + dp2[j - 2]) * (j * (j-1))/2; //2 in the row
			if (i > 0) dp3[j] += (1 + dp1[j-1]) * j  * (i-1);//one col, 2 in the col
			dp3[j] %= mod;
		}
		dp1 = dp2;
		dp2 = dp3;
	}
	return dp2[m];
}

int main() {
	int n, m;
	cin >> n >> m;

	cout << func(n, m) << endl;
	return 0;
}

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