Submission #474798

#	Time	Username	Problem	Language	Result	Execution time	Memory
474798		SirCovidThe19th	Kangaroo (CEOI16_kangaroo)	C++17	100 / 100	30 ms	31748 KiB

kangaroo

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

int main(){
    int n, a, b; cin >> n >> a >> b; 
    long long dp[n + 1][n + 1] = {}; dp[0][0] = 1;
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= n; j++){
            if (i == a or i == b) 
                dp[i][j] = dp[i - 1][j] + dp[i - 1][j - 1];
            else 
                dp[i][j] = (dp[i - 1][j + 1] * j) + (dp[i - 1][j - 1] * (j - (i > a) - (i > b)));
            dp[i][j] %= 1000000007;
        }
    }
    cout<<dp[n][1]<<endl;
}

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