oj.uz

Submission #59108

# Submission time Handle Problem Language Result Execution time Memory
59108 2018-07-20T14:42:51 Z joaogui1 Kangaroo (CEOI16_kangaroo) C++14
100 / 100
 123 ms 32508 KB 
#include <cstring>
#include <iostream>

//using namespace std;
typedef long long int ll;

int sta, end, n;
ll dp[2010][2010];
static ll MOD = 1000000007;


ll f(int i, int k){
  if(k < 0) return 0;
  if(i == n - 1)  return k == 0;

  ll ks = i > sta;
  ll ke = i > end;

  ll &ret = dp[i][k];
  if(ret != -1) return ret;
  ret = 0;

  if(i == sta || i == end){
    ret += f(i + 1, k);
    ret += f(i + 1, k - 1)*k;
  }
  else{
    ret += f(i + 1, k + 1);
    ret += f(i + 1, k - 1)*k*(k - 1 + ks + ke);
  }

  return (ret %= MOD);
}

int main(){
  std::cin.tie(0);
  memset(dp, -1, sizeof dp);
  std::ios_base::sync_with_stdio(0);
  std::cin >> n >> sta >> end;
  --sta, --end;
  std::cout << f(0, 0) << "\n";

  return 0;
}

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 31864 KB Output is correct
2 Correct 25 ms 31972 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 31864 KB Output is correct
2 Correct 25 ms 31972 KB Output is correct
3 Correct 24 ms 32024 KB Output is correct
4 Correct 31 ms 32212 KB Output is correct
5 Correct 25 ms 32212 KB Output is correct
6 Correct 33 ms 32212 KB Output is correct
7 Correct 27 ms 32236 KB Output is correct
8 Correct 27 ms 32252 KB Output is correct
9 Correct 32 ms 32380 KB Output is correct
10 Correct 27 ms 32380 KB Output is correct
11 Correct 25 ms 32380 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 31864 KB Output is correct
2 Correct 25 ms 31972 KB Output is correct
3 Correct 24 ms 32024 KB Output is correct
4 Correct 31 ms 32212 KB Output is correct
5 Correct 25 ms 32212 KB Output is correct
6 Correct 33 ms 32212 KB Output is correct
7 Correct 27 ms 32236 KB Output is correct
8 Correct 27 ms 32252 KB Output is correct
9 Correct 32 ms 32380 KB Output is correct
10 Correct 27 ms 32380 KB Output is correct
11 Correct 25 ms 32380 KB Output is correct
12 Correct 27 ms 32380 KB Output is correct
13 Correct 30 ms 32380 KB Output is correct
14 Correct 31 ms 32380 KB Output is correct
15 Correct 26 ms 32380 KB Output is correct
16 Correct 28 ms 32380 KB Output is correct
17 Correct 26 ms 32380 KB Output is correct
18 Correct 26 ms 32380 KB Output is correct
19 Correct 33 ms 32380 KB Output is correct
20 Correct 25 ms 32380 KB Output is correct

Subtask #4
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 31864 KB Output is correct
2 Correct 25 ms 31972 KB Output is correct
3 Correct 24 ms 32024 KB Output is correct
4 Correct 31 ms 32212 KB Output is correct
5 Correct 25 ms 32212 KB Output is correct
6 Correct 33 ms 32212 KB Output is correct
7 Correct 27 ms 32236 KB Output is correct
8 Correct 27 ms 32252 KB Output is correct
9 Correct 32 ms 32380 KB Output is correct
10 Correct 27 ms 32380 KB Output is correct
11 Correct 25 ms 32380 KB Output is correct
12 Correct 27 ms 32380 KB Output is correct
13 Correct 30 ms 32380 KB Output is correct
14 Correct 31 ms 32380 KB Output is correct
15 Correct 26 ms 32380 KB Output is correct
16 Correct 28 ms 32380 KB Output is correct
17 Correct 26 ms 32380 KB Output is correct
18 Correct 26 ms 32380 KB Output is correct
19 Correct 33 ms 32380 KB Output is correct
20 Correct 25 ms 32380 KB Output is correct
21 Correct 38 ms 32380 KB Output is correct
22 Correct 49 ms 32380 KB Output is correct
23 Correct 41 ms 32380 KB Output is correct
24 Correct 117 ms 32508 KB Output is correct
25 Correct 109 ms 32508 KB Output is correct
26 Correct 95 ms 32508 KB Output is correct
27 Correct 123 ms 32508 KB Output is correct
28 Correct 68 ms 32508 KB Output is correct