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Submission #316400

# Submission time Handle Problem Language Result Execution time Memory
316400 2020-10-26T09:08:20 Z nouvo25 Kangaroo (CEOI16_kangaroo) C++14
100 / 100
 33 ms 14208 KB 
#include <bits/stdc++.h>
#define fi first
#define se second
#define ll long long
#define io ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)

using namespace std;

const int MOD = 1e9 + 7, MAXN = 2007;

int dp[MAXN][MAXN] = {}, n, cs, cf;

void add(int &a, const int &b)
{
	a += b;
	if (a >= MOD) a -= MOD;
}

int main()
{
//	freopen("test.INP","r",	stdin);
	io;
	cin >> n >> cs >> cf;
	
	dp[0][0] = 1;
	for (int i = 1; i < n; ++i)
	{
		for (int j = 0; j <= i; ++j)
		{
			if (i == cs || i == cf)
			{
				add(dp[i][j], dp[i - 1][j]);
				add(dp[i][j], 1LL*(j + 1)*dp[i - 1][j + 1] % MOD);
			}else
			{
				add(dp[i][j], 1LL*j*(j + 1)*dp[i - 1][j + 1] % MOD);
				if (j) add(dp[i][j], dp[i - 1][j - 1]);
				if (i > cs) add(dp[i][j], 1LL*(j + 1)*dp[i - 1][j + 1] % MOD);
				if (i > cf) add(dp[i][j], 1LL*(j + 1)*dp[i - 1][j + 1] % MOD);
			}
		}
	}

	cout << dp[n - 1][0];
	return 0;
}

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 1 ms 512 KB Output is correct
5 Correct 1 ms 512 KB Output is correct
6 Correct 1 ms 512 KB Output is correct
7 Correct 1 ms 512 KB Output is correct
8 Correct 1 ms 512 KB Output is correct
9 Correct 1 ms 512 KB Output is correct
10 Correct 1 ms 512 KB Output is correct
11 Correct 1 ms 512 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 1 ms 512 KB Output is correct
5 Correct 1 ms 512 KB Output is correct
6 Correct 1 ms 512 KB Output is correct
7 Correct 1 ms 512 KB Output is correct
8 Correct 1 ms 512 KB Output is correct
9 Correct 1 ms 512 KB Output is correct
10 Correct 1 ms 512 KB Output is correct
11 Correct 1 ms 512 KB Output is correct
12 Correct 1 ms 1152 KB Output is correct
13 Correct 1 ms 1152 KB Output is correct
14 Correct 1 ms 1152 KB Output is correct
15 Correct 1 ms 1280 KB Output is correct
16 Correct 1 ms 1152 KB Output is correct
17 Correct 1 ms 1280 KB Output is correct
18 Correct 1 ms 1152 KB Output is correct
19 Correct 1 ms 1152 KB Output is correct
20 Correct 1 ms 1280 KB Output is correct

Subtask #4
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 1 ms 512 KB Output is correct
5 Correct 1 ms 512 KB Output is correct
6 Correct 1 ms 512 KB Output is correct
7 Correct 1 ms 512 KB Output is correct
8 Correct 1 ms 512 KB Output is correct
9 Correct 1 ms 512 KB Output is correct
10 Correct 1 ms 512 KB Output is correct
11 Correct 1 ms 512 KB Output is correct
12 Correct 1 ms 1152 KB Output is correct
13 Correct 1 ms 1152 KB Output is correct
14 Correct 1 ms 1152 KB Output is correct
15 Correct 1 ms 1280 KB Output is correct
16 Correct 1 ms 1152 KB Output is correct
17 Correct 1 ms 1280 KB Output is correct
18 Correct 1 ms 1152 KB Output is correct
19 Correct 1 ms 1152 KB Output is correct
20 Correct 1 ms 1280 KB Output is correct
21 Correct 5 ms 3840 KB Output is correct
22 Correct 6 ms 4096 KB Output is correct
23 Correct 6 ms 4480 KB Output is correct
24 Correct 30 ms 14208 KB Output is correct
25 Correct 31 ms 14204 KB Output is correct
26 Correct 31 ms 14200 KB Output is correct
27 Correct 33 ms 14072 KB Output is correct
28 Correct 20 ms 10240 KB Output is correct