Submission #1236295

#	Time	Username	Problem	Language	Result	Execution time	Memory
1236295		AmirAli_H1	Asceticism (JOI18_asceticism)	C++20	49 / 100	40 ms	46916 KiB

asceticism

// In the name of Allah

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

typedef		long long int			ll;
typedef		long double				ld;
typedef		pair<int, int>			pii;
typedef		pair<ll, ll>			pll;
typedef		complex<ld>				cld;

#define		all(x)					(x).begin(),(x).end()
#define		len(x)					((ll) (x).size())
#define		F						first
#define		S						second
#define		pb						push_back
#define		sep						' '
#define		endl					'\n'
#define		Mp						make_pair
#define		kill(x)					cout << x << '\n', exit(0)
#define		set_dec(x)				cout << fixed << setprecision(x);
#define		file_io(x,y)			freopen(x, "r", stdin); freopen(y, "w", stdout);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int maxn = 3000 + 4;
const int mod = 1e9 + 7;

int n, k;
ll dp[maxn][maxn];

void solve() {
	cin >> n >> k; k--;
	dp[1][0] = 1;
	for (int i = 1; i < n; i++) {
		for (int j = 0; j < i; j++) {
			(dp[i + 1][j] += dp[i][j] * (j + 1)) %= mod;
			(dp[i + 1][j + 1] += dp[i][j] * (i - j)) %= mod;
		}
	}
	cout << dp[n][k] << endl;
}

int main() {
	ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);

	int T = 1;
	while (T--) {
		solve();
	}

	return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 20 / 20
• Subtask 3: 25 / 25
• Subtask 4: 0 / 51