Submission #535161

#	Time	Username	Problem	Language	Result	Execution time	Memory
535161		Lobo	Tents (JOI18_tents)	C++17	100 / 100	113 ms	71400 KiB

tents

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

const long long inf = (long long) 1e18 + 10;
const int inf1 = (int) 1e9 + 10;
#define int long long
#define dbl long double
#define endl '\n'
#define sc second
#define fr first
#define mp make_pair
#define pb push_back
#define all(x) x.begin(), x.end()

#define maxn 3030

int dp[maxn][maxn];
int mod = 1e9+7;

void solve() {
    int n, m;
    cin >> n >> m;

    int ans = 0;
    dp[n][m] = 1;
    for(int i = n; i >= 0; i--) {
        for(int j = m; j >= 0; j--) {
            dp[i][j]+= dp[i+1][j];

            dp[i][j]+= dp[i+1][j+1]*(j+1)*4;

            dp[i][j]+= dp[i+1][j+2]*(j+2)*(j+1)/2;

            dp[i][j]+= dp[i+2][j+1]*(j+1)*(i+1);

            dp[i][j]%= mod;

            // cout << i << " " << j << " " << dp[i][j] << endl;
        }
    }

    for(int j = m; j >= 0; j--) ans+= dp[0][j];

    cout << (ans-1+mod)%mod << endl;
}

int32_t main() {
    ios::sync_with_stdio(false); cin.tie(0);

    // freopen("in.in", "r", stdin);
    //freopen("out.out", "w", stdout);

    int tt = 1;
    // cin >> tt;
    while(tt--) solve();

}

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