Submission #45221

#	Time	Username	Problem	Language	Result	Execution time	Memory
45221		sorry_Benq	Kangaroo (CEOI16_kangaroo)	C++17	36 / 100	6 ms	1620 KiB

kangaroo

#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;

int DPplus[41][41][41];
int DPminus[41][41][41];

int main(){
	int N, cs, cf; cin >> N >> cs >> cf;
	DPplus[2][1][2] = 1LL;
	DPminus[2][2][1] = 1LL;
	for (int i = 3; i <= 40; i++){
		for (int k = 1; k <= i; k++){
			for (int j = 1; j <= i; j++){
				if (k == j) continue;
				DPplus[i][j][k] = 0LL;
				DPminus[i][j][k] = 0LL;
				for (int l = 1; l <= j - 1; l++){
					int eps = (k > j);
					DPminus[i][j][k] += DPplus[i - 1][l][k - eps];
					DPminus[i][j][k] %= MOD;
				}
				for (int l = j + 1; l <= i; l++){
					int eps = (k > j);
					DPplus[i][j][k] += DPminus[i - 1][l - 1][k - eps];
					DPplus[i][j][k] %= MOD; 
				}
			}
		}
	}
	cout << (DPplus[N][cs][cf] + DPminus[N][cs][cf]) % MOD << endl;
}

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