Submission #1242436

#	Time	Username	Problem	Language	Result	Execution time	Memory
1242436		ghammazhassan	Kangaroo (CEOI16_kangaroo)	C++20	6 / 100	0 ms	324 KiB

kangaroo

// #include <bits/stdc++.h>
#include <iostream>
#include <cmath>
#include <algorithm>
#include <map>
#include <unordered_map>
#include <vector>
#include <iomanip>
#include <string>
#include <queue>
#include <set>
#include <deque>
using namespace std;
#define int long long
#define endl "\n"
#define fi first
#define se second
const int M=998244353;
// const int inf = 3e9;
const int LOG=19;
const int N=2e3+5;
int n , m , c , w , k , t=1 , q=1 , x , y , z , l , r;
int dp[N][N][3];

void solve()
{	
	cin >> n >> x >> y;
	if (x==1 or y==1){
		dp[1][1][1]=1;
	}
	else{
		dp[1][1][0]=1;
	}
	for (int i=1;i<n;i++){
		for (int j=1;j<=i;j++){
			if (x==i+1 or y==i+1){
				for (int k=0;k<2;k++){
					dp[i+1][j+1][k+1]+=dp[i][j][k];
					dp[i+1][j][k+1]+=dp[i][j][k];
				}
			}
			else{
				for (int k=0;k<3;k++){
					dp[i+1][j+1][k]+=dp[i][j][k]*(j+1-k);
					// dp[i+1][j][k]+=dp[i][j][k]*(2*j-k);
					dp[i+1][j-1][k]+=dp[i][j][k]*(j-1);
				}
			}
		}
	}
	cout << dp[n][1][2] << endl;

}
signed main()	
{

	ios::sync_with_stdio(0);//DO NOT USE IN INTERACTIVE
	cin.tie(0), cout.tie(0);//DO NOT USE IN INTERACTIVE
	cout << fixed<<setprecision(9);
	srand(time(0));
	// int t=1;
	// cin >> t;
	for (int _=1;_<=t;_++){
		solve();
		q++;
	}
}  

• Subtask 1: 6 / 6
• Subtask 2: 0 / 30
• Subtask 3: 0 / 15
• Subtask 4: 0 / 49