Submission #920464

#	Time	Username	Problem	Language	Result	Execution time	Memory
920464		adaawf	Tents (JOI18_tents)	C++14	100 / 100	137 ms	70816 KiB

tents

#include <iostream>
using namespace std;
long long int f[3005][3005], mod = 1e9 + 7;
int main() {
    int n, m;
    cin >> n >> m;
    for (int i = 0; i <= n; i++) {
        for (int j = 0; j <= m; j++) {
            if (i == 0 || j == 0) f[i][j] = 1;
            else {
                f[i][j] = f[i - 1][j];
                f[i][j] += f[i - 1][j - 1] * j * 4;
                if (j >= 2) f[i][j] += f[i - 1][j - 2] * (j * (j - 1) / 2) % mod;
                if (i >= 2) f[i][j] += f[i - 2][j - 1] * (i - 1) * j;
                f[i][j] %= mod;
            }
        }
    }
    cout << (f[n][m] + mod - 1) % mod;
}

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