답안 #125567

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
125567	2019-07-06T00:29:48 Z	tutis	캥거루 (CEOI16_kangaroo)	C++17	51 / 100	2000 ms	322920 KB

kangaroo

/*input
10 2 3
*/
#pragma GCC optimize ("O3")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
const ll modulo = 1000000007;
int sgn(ll x)
{
	if (x < 0)
		return -1;
	if (x > 0)
		return 1;
	return 0;
}
map<tuple<int, int, int, int>, ll>M;
ll f(int n, int a, int b, int s)
{
	if (a == b)
		return 0;
	if (M.count(make_tuple(n, a, b, s)))
		return M[make_tuple(n, a, b, s)];
	if (n == 2)
	{
		if (sgn(b - a) != s)
			return 0;
		else
			return 1;
	}
	ll ret = 0;
	for (int c = 1; c <= n; c++)
	{
		if (sgn(b - c) == s)
		{
			ret += f(n - 1, a - (a > b), c - (c > b), -s);
		}
	}
	ret %= modulo;
	return M[make_tuple(n, a, b, s)] = ret;
}
ll f(int n, int a, int b)
{
	ll ans = f(n, a, b, 1) + f(n, a, b, -1);
	ans %= modulo;
	return ans;
}
ll fast(int N, int A, int B)
{
	ll L[N + 1][N + 1][N + 1];
	ll R[N + 1][N + 1][N + 1];
	for (int n = 2; n <= N; n++)
	{
		for (int a = 1; a <= n; a++)
		{
			for (int b = 1; b <= n; b++)
			{
				L[n][a][b] = 0;
				R[n][a][b] = 0;
				if (a == b)
					continue;
				if (n == 2)
				{
					if (a > b)
					{
						L[n][a][b] = 1;
					}
					if (a < b)
					{
						R[n][a][b] = 1;
					}
				}
				else
				{
					for (int c = 1; c <= n; c++)
					{
						if (c > b)
						{
							L[n][a][b] += R[n - 1][a - (a > b)][c - (c > b)];
						}
						if (c < b)
						{
							R[n][a][b] += L[n - 1][a - (a > b)][c - (c > b)];
						}
					}
				}
				L[n][a][b] %= modulo;
				R[n][a][b] %= modulo;
			}
		}
	}
	ll ret = L[N][A][B] + R[N][A][B];
	ret %= modulo;
	return ret;
}
int main()
{
	int n, a, b;
	cin >> n >> a >> b;
	//cout << f(n, a, b) << "\n";
	cout << fast(n, a, b) << "\n";
}

Subtask #1

6.0 / 6.0

#	결과	실행 시간	메모리	Grader output
1	Correct	2 ms	380 KB	Output is correct
2	Correct	2 ms	256 KB	Output is correct

Subtask #2

30.0 / 30.0

#	결과	실행 시간	메모리	Grader output
1	Correct	2 ms	380 KB	Output is correct
2	Correct	2 ms	256 KB	Output is correct
3	Correct	2 ms	504 KB	Output is correct
4	Correct	4 ms	1144 KB	Output is correct
5	Correct	4 ms	1144 KB	Output is correct
6	Correct	4 ms	1144 KB	Output is correct
7	Correct	3 ms	1016 KB	Output is correct
8	Correct	4 ms	1016 KB	Output is correct
9	Correct	4 ms	1144 KB	Output is correct
10	Correct	4 ms	1144 KB	Output is correct
11	Correct	4 ms	1016 KB	Output is correct

Subtask #3

15.0 / 15.0

#	결과	실행 시간	메모리	Grader output
1	Correct	2 ms	380 KB	Output is correct
2	Correct	2 ms	256 KB	Output is correct
3	Correct	2 ms	504 KB	Output is correct
4	Correct	4 ms	1144 KB	Output is correct
5	Correct	4 ms	1144 KB	Output is correct
6	Correct	4 ms	1144 KB	Output is correct
7	Correct	3 ms	1016 KB	Output is correct
8	Correct	4 ms	1016 KB	Output is correct
9	Correct	4 ms	1144 KB	Output is correct
10	Correct	4 ms	1144 KB	Output is correct
11	Correct	4 ms	1016 KB	Output is correct
12	Correct	772 ms	63992 KB	Output is correct
13	Correct	609 ms	53324 KB	Output is correct
14	Correct	777 ms	63984 KB	Output is correct
15	Correct	789 ms	65056 KB	Output is correct
16	Correct	772 ms	64120 KB	Output is correct
17	Correct	790 ms	65088 KB	Output is correct
18	Correct	503 ms	46200 KB	Output is correct
19	Correct	743 ms	62200 KB	Output is correct
20	Correct	796 ms	65060 KB	Output is correct

Subtask #4

0 / 49.0

#	결과	실행 시간	메모리	Grader output
1	Correct	2 ms	380 KB	Output is correct
2	Correct	2 ms	256 KB	Output is correct
3	Correct	2 ms	504 KB	Output is correct
4	Correct	4 ms	1144 KB	Output is correct
5	Correct	4 ms	1144 KB	Output is correct
6	Correct	4 ms	1144 KB	Output is correct
7	Correct	3 ms	1016 KB	Output is correct
8	Correct	4 ms	1016 KB	Output is correct
9	Correct	4 ms	1144 KB	Output is correct
10	Correct	4 ms	1144 KB	Output is correct
11	Correct	4 ms	1016 KB	Output is correct
12	Correct	772 ms	63992 KB	Output is correct
13	Correct	609 ms	53324 KB	Output is correct
14	Correct	777 ms	63984 KB	Output is correct
15	Correct	789 ms	65056 KB	Output is correct
16	Correct	772 ms	64120 KB	Output is correct
17	Correct	790 ms	65088 KB	Output is correct
18	Correct	503 ms	46200 KB	Output is correct
19	Correct	743 ms	62200 KB	Output is correct
20	Correct	796 ms	65060 KB	Output is correct
21	Execution timed out	2086 ms	322920 KB	Time limit exceeded
22	Halted	0 ms	0 KB	-