Submission #1206768

#	Time	Username	Problem	Language	Result	Execution time	Memory
1206768		errorgorn	Festivals in JOI Kingdom 2 (JOI23_festival2)	C++20	0 / 100	1 ms	580 KiB

festival2

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

#define int long long
#define ii pair<int,int>
#define iii tuple<int,int,int>
#define fi first
#define se second
#define endl '\n'

#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define lb lower_bound
#define ub upper_bound

#define rep(x,start,end) for(int x=(start)-((start)>(end));x!=(end)-((start)>(end));((start)<(end)?x++:x--))
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());

int n,MOD;
int dp[2][20005]; //m-1
int dp2[2][20005]; //m

signed main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin.exceptions(ios::badbit | ios::failbit);
	
	cin>>n>>MOD;
	
	int a=0,b=1;
	dp[a][2]=1;
	
	rep(x,2,n+1){
		memset(dp[b],0,sizeof(dp[b]));
		
		rep(y,0,20005) if (dp[a][y]){
			dp[b][2]=(dp[b][2]+dp[a][y])%MOD;
			dp[b][y+1]=(dp[b][y+1]+dp[a][y]*(2*(x-1)-y))%MOD;
			dp2[b][1]=(dp2[b][1]+dp[a][y]*y)%MOD;
		}
		rep(y,0,20005) if (dp2[a][y]){
			dp[b][2+y]=(dp[b][2+y]+dp2[a][y])%MOD;
			dp2[b][y+1]=(dp2[b][y+1]+dp2[a][y]*(2*(x-1)-y))%MOD;
		}
		
		swap(a,b);
	}
	
	int ans=0;
	rep(y,0,20005) ans=(ans+dp[a][y]+dp2[a][y])%MOD;
	
	// cout<<ans<<endl;
	
	int tot=1;
	rep(x,1,n+1) tot=tot*(2*x-1)%MOD;
	
	cout<<(tot-ans+MOD)%MOD<<endl;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 5
• Subtask 3: 0 / 27
• Subtask 4: 0 / 14
• Subtask 5: 0 / 36
• Subtask 6: 0 / 13