oj.uz

답안 #165796

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
165796 2019-11-28T22:31:15 Z luciocf 캥거루 (CEOI16_kangaroo) C++14
100 / 100
 80 ms 16324 KB 
#include <bits/stdc++.h>

using namespace std;

const int maxn = 2e3+10;
const int mod = 1e9+7;

int n;
int cs, cf;

int dp[maxn][maxn];

int solve(int pos, int cc)
{
	if (pos == n+1 && cc != 1) return 0;
	if (pos == n+1) return 1;
	if (dp[pos][cc] != -1) return dp[pos][cc];

	int ans = 0;

	if (pos == cs || pos == cf)
	{
		ans = (ans + solve(pos+1, cc))%mod;
		ans = (ans + solve(pos+1, cc+1))%mod;
		return dp[pos][cc] = ans;
	}

	if (cc >= 2)
	{
		ans = (1ll*ans + 1ll*(cc-1)*solve(pos+1, cc+1))%mod;
		ans = (1ll*ans + 1ll*(cc-1)*solve(pos+1, cc-1))%mod;
	}

	if (pos < cs)
		ans = (1ll*ans + 1ll*solve(pos+1, cc+1))%mod;

	if (pos < cf)
		ans = (1ll*ans + 1ll*solve(pos+1, cc+1))%mod;

	return dp[pos][cc] = ans;
}

int main(void)
{
	scanf("%d %d %d", &n, &cs, &cf);

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

	memset(dp, -1, sizeof dp);

	printf("%d\n", solve(2, 1));
}

Compilation message

kangaroo.cpp: In function 'int main()':
kangaroo.cpp:45:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d %d", &n, &cs, &cf);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
6.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 15 ms 16120 KB Output is correct
2 Correct 15 ms 16120 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 15 ms 16120 KB Output is correct
2 Correct 15 ms 16120 KB Output is correct
3 Correct 16 ms 16120 KB Output is correct
4 Correct 15 ms 16120 KB Output is correct
5 Correct 17 ms 16120 KB Output is correct
6 Correct 15 ms 16120 KB Output is correct
7 Correct 15 ms 16120 KB Output is correct
8 Correct 15 ms 16120 KB Output is correct
9 Correct 15 ms 16120 KB Output is correct
10 Correct 15 ms 16120 KB Output is correct
11 Correct 15 ms 16120 KB Output is correct

Subtask #3
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 15 ms 16120 KB Output is correct
2 Correct 15 ms 16120 KB Output is correct
3 Correct 16 ms 16120 KB Output is correct
4 Correct 15 ms 16120 KB Output is correct
5 Correct 17 ms 16120 KB Output is correct
6 Correct 15 ms 16120 KB Output is correct
7 Correct 15 ms 16120 KB Output is correct
8 Correct 15 ms 16120 KB Output is correct
9 Correct 15 ms 16120 KB Output is correct
10 Correct 15 ms 16120 KB Output is correct
11 Correct 15 ms 16120 KB Output is correct
12 Correct 16 ms 16120 KB Output is correct
13 Correct 15 ms 16104 KB Output is correct
14 Correct 16 ms 16120 KB Output is correct
15 Correct 16 ms 16120 KB Output is correct
16 Correct 16 ms 16120 KB Output is correct
17 Correct 17 ms 16120 KB Output is correct
18 Correct 17 ms 16140 KB Output is correct
19 Correct 15 ms 16092 KB Output is correct
20 Correct 17 ms 16120 KB Output is correct

Subtask #4
49.0 / 49.0

# 결과 실행 시간 메모리 Grader output
1 Correct 15 ms 16120 KB Output is correct
2 Correct 15 ms 16120 KB Output is correct
3 Correct 16 ms 16120 KB Output is correct
4 Correct 15 ms 16120 KB Output is correct
5 Correct 17 ms 16120 KB Output is correct
6 Correct 15 ms 16120 KB Output is correct
7 Correct 15 ms 16120 KB Output is correct
8 Correct 15 ms 16120 KB Output is correct
9 Correct 15 ms 16120 KB Output is correct
10 Correct 15 ms 16120 KB Output is correct
11 Correct 15 ms 16120 KB Output is correct
12 Correct 16 ms 16120 KB Output is correct
13 Correct 15 ms 16104 KB Output is correct
14 Correct 16 ms 16120 KB Output is correct
15 Correct 16 ms 16120 KB Output is correct
16 Correct 16 ms 16120 KB Output is correct
17 Correct 17 ms 16120 KB Output is correct
18 Correct 17 ms 16140 KB Output is correct
19 Correct 15 ms 16092 KB Output is correct
20 Correct 17 ms 16120 KB Output is correct
21 Correct 22 ms 16120 KB Output is correct
22 Correct 24 ms 16136 KB Output is correct
23 Correct 24 ms 16248 KB Output is correct
24 Correct 80 ms 16324 KB Output is correct
25 Correct 59 ms 16248 KB Output is correct
26 Correct 77 ms 16248 KB Output is correct
27 Correct 76 ms 16248 KB Output is correct
28 Correct 43 ms 16176 KB Output is correct