Submission #100558

#	Time	Username	Problem	Language	Result	Execution time	Memory
100558		JPN20	Asceticism (JOI18_asceticism)	C++17	49 / 100	302 ms	142256 KiB

asceticism

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

long long dp[3009][3009], mod = 1000000007;

long long solve(long long N, long long K) {
	for (int i = 0; i <= N; i++) { for (int j = 0; j <= N; j++) dp[i][j] = 0; }
	
	dp[0][0] = 1;
	for (int i = 0; i < N; i++) {
		for (int j = 0; j < N; j++) {
			dp[i + 1][j] += 1LL * (1LL + j) * dp[i][j]; dp[i + 1][j] %= mod;
			dp[i + 1][j + 1] += 1LL * (i - j) * dp[i][j]; dp[i + 1][j + 1] %= mod;
		}
	}
	return dp[N][K - 1];
}

int main() {
	long long A, B; cin >> A >> B;
	cout << solve(A, B) << endl;
	return 0;
}

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