#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#define fi first
#define se second
#define ll long long
#define pb push_back
#define ii pair<int,int>
template <class T>
using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const int nax=3e3+5;
const int MOD=1e9+7;
#define optimise ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
long long dp[nax][nax];
long long dfs(ll x,ll y){
if(x<0||y<0) return 0;
if(x==0) return 1;
if(dp[x][y]) return dp[x][y];
dp[x][y]+=dfs(x-1,y-2)*(y*(y-1)/2)%MOD;
dp[x][y]%=MOD;
dp[x][y]+=dfs(x-1,y)%MOD;
dp[x][y]%=MOD;
dp[x][y]+=dfs(x-1,y-1)*(y*4)%MOD;
dp[x][y]%=MOD;
dp[x][y]+=dfs(x-2,y-1)*(y*(x-1))%MOD;
dp[x][y]%=MOD;
return dp[x][y];
}
int main()
{
#ifndef ONLINE_JUDGE
int n,m;
cin>>n>>m;
dp[0][0]=1;
cout << dfs(n,m)-1<<endl;
}
Compilation message
tents.cpp:34: error: unterminated #ifndef
34 | #ifndef ONLINE_JUDGE
|
