Submission #1077675

#	Time	Username	Problem	Language	Result	Execution time	Memory
1077675		Martincho506	Tents (JOI18_tents)	C++17	100 / 100	306 ms	117192 KiB

tents

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

long long mod = 1000000007, vis[3001][3001], dp[3001][3001];

long long f(long long i, long long j)
{
    if(i == 0 || j == 0) return 1;
    if(i < 0 || j < 0) return 0;
    if(vis[i][j]) return dp[i][j];
    vis[i][j] = true;
    dp[i][j] = ((f(i-1, j)+4*j*f(i-1, j-1))%mod+(f(i-1, j-2)*j*(j-1)/2)%mod+(f(i-2, j-1)*j*(i-1))%mod)%mod;
    return dp[i][j];
}

int main()
{
    long long n, m;
    cin>>n>>m;
    cout<<f(n, m)-1;
    return 0;
}

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