Submission #591135

# Submission time Handle Problem Language Result Execution time Memory
591135 2022-07-06T22:13:56 Z blue Kangaroo (CEOI16_kangaroo) C++17
100 / 100
26 ms 16004 KB
#include <iostream>
#include <vector>
using namespace std;

using ll = long long;
const ll mod = 1'000'000'007LL;


ll ad(ll a, ll b)
{
	return (a+b)%mod;
}

ll mul(ll a, ll b)
{
	return (a*b)%mod;
}

void selfadd(int& a, int b)
{
	a = ad(a, b);
}


int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

	int N, cs, cf;
	cin >> N >> cs >> cf;

	if(cs > cf)
		swap(cs, cf);

	int DP[1+N][2+N];
	for(int i = 0; i <= N; i++)
		for(int j = 0; j <= 1+N; j++)
			DP[i][j] = 0;

	DP[0][1] = 1;

	for(int i = 1; i <= N; i++)
	{
		for(int j = 0; j <= 1+i; j++)
		{
			if(i == cs || i == cf)
			{
				selfadd(DP[i][j], DP[i-1][j]);
				if(j+1 <= N+1)
					selfadd(DP[i][j], DP[i-1][j+1]);
			}
			else
			{
				if(j >= 1)
					selfadd(DP[i][j], mul(j-1, DP[i-1][j-1]));

				if(j+1 <= N+1 && j+1 - (i < cs) - (i < cf) >= 0)
					selfadd(DP[i][j], mul(j+1 - (i < cs) - (i < cf), DP[i-1][j+1]));
			}

			// cerr << i << ' ' << j << " : " << DP[i][j] << '\n';
		}
	}

	cout << DP[N][0] << '\n';
}
# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 324 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 324 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 1 ms 468 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 1 ms 468 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 1 ms 452 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 1 ms 596 KB Output is correct
20 Correct 1 ms 468 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 324 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 1 ms 468 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 1 ms 468 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 1 ms 452 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 1 ms 596 KB Output is correct
20 Correct 1 ms 468 KB Output is correct
21 Correct 3 ms 2004 KB Output is correct
22 Correct 4 ms 2132 KB Output is correct
23 Correct 5 ms 2516 KB Output is correct
24 Correct 23 ms 16004 KB Output is correct
25 Correct 26 ms 15992 KB Output is correct
26 Correct 25 ms 15956 KB Output is correct
27 Correct 26 ms 15828 KB Output is correct
28 Correct 14 ms 9028 KB Output is correct