Submission #1014356

#	Time	Username	Problem	Language	Result	Execution time	Memory
1014356		MarwenElarbi	Tents (JOI18_tents)	C++17	100 / 100	166 ms	58960 KiB

tents

#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()
{
    optimise; 
    int n,m;
    cin>>n>>m;
    dp[0][0]=1;
    cout << dfs(n,m)-1<<endl;
}

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