Submission #813808

#	Time	Username	Problem	Language	Result	Execution time	Memory
813808		andecaandeci	Tents (JOI18_tents)	C++17	48 / 100	295 ms	217096 KiB

tents

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ld long double
#define ull unsigned long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define fi first
#define se second

const int N = 3e2 + 5;
const int mod = 1e9 + 7;

ll dp[N][N][N];

int main() { 
    ios_base::sync_with_stdio(false); cin.tie(NULL);
    int h, w;
    cin >> h >> w;
    dp[0][w][0] = 1;
    for (int i = 0; i < h; i++) {
        for (int j = w; j >= 0; j--) {
            for (int k = h; k >= 0; k--) {
                if (j >= 2) {
                    dp[i + 1][j - 2][k] += j * (j - 1) / 2 * dp[i][j][k];
                    dp[i + 1][j - 2][k] %= mod;
                }
                if (j >= 1) {
                    dp[i + 1][j - 1][k] += 4 * j * dp[i][j][k];
                    dp[i + 1][j - 1][k] %= mod;
                    if (k >= 1) {
                        dp[i + 1][j - 1][k - 1] += ((j * k) % mod) * dp[i][j][k];
                        dp[i + 1][j - 1][k - 1] %= mod;
                    }
                }
                dp[i + 1][j][k + 1] += dp[i][j][k];
                dp[i + 1][j][k + 1] %= mod;
            }
        }
    }
    ll ans = 0;
    for (int i = 0; i < w; i++) {
        for (int j = 0; j <= h; j++) {
            ans += dp[h][i][j];
            ans %= mod;
        }
    }
    cout << ans << "\n";
    // for (int i = 0; i <= h; i++) {
    //     for (int j = 0; j <= w; j++) {
    //         cout << i << " " << j << "gvawp\n";
    //         for (int k = 0; k <= w; k++) cout << dp[i][j][k] << " ";
    //         cout << "\n";
    //     }
    // }
}  

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