제출 #1245141

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1245141		PlayVoltz	캥거루 (CEOI16_kangaroo)	C++20	100 / 100	20 ms	31816 KiB

kangaroo

#include <cstdio>
#include <stdio.h>
#include <stdbool.h>
#include <iostream>
#include <map>
#include <vector>
#include <climits>
#include <stack>
#include <string>
#include <queue>
#include <algorithm>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <cmath>
#include <cctype>
#include <bitset>
#include <iomanip>
#include <cstring>
#include <numeric>
#include <cassert>
#include <random>
#include <chrono>
#include <fstream>
using namespace std;

#define int long long
#define pii pair<int, int>
#define mp make_pair
#define pb push_back
#define fi first
#define se second

const int MOD = 1000000007;

int32_t main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int n, a, b;
	cin>>n>>a>>b;
	vector<vector<int> > dp(n+1, vector<int>(n+2, 0));
	dp[0][0]=1;
	for (int i=1; i<=n; ++i)for (int j=1; j<=i; ++j){
		if (i==a||i==b)dp[i][j]=(dp[i][j]+dp[i-1][j-1]+dp[i-1][j])%MOD;
		else dp[i][j]=(dp[i][j]+j*dp[i-1][j+1]+max(0ll, j-(i>a)-(i>b))*dp[i-1][j-1])%MOD;
	}
	cout<<dp[n][1];
}

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