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Submission #789266

# Submission time Handle Problem Language Result Execution time Memory
789266 2023-07-21T08:44:01 Z cig32 Kangaroo (CEOI16_kangaroo) C++17
100 / 100
 21 ms 31948 KB 
#include "bits/stdc++.h"
using namespace std;
#define int long long
const int MAXN = 2023;
const int MOD = 1e9 + 7;
int dp[MAXN][MAXN], n, a, b;
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cin >> n >> a >> b;
  if(a > b) swap(a, b);
  dp[1][1] = 1;
  for(int i=2; i<=n; i++) {
    for(int j=1; j<=n; j++) {
      if(i == a || i == b) {
        dp[i][j] = (dp[i-1][j-1] + dp[i-1][j]) % MOD;
      }
      else if(i < a) {
        dp[i][j] = (j * dp[i-1][j-1] + j * dp[i-1][j+1]) % MOD;
      }
      else if(a < i && i < b) {
        dp[i][j] = ((j-1) * dp[i-1][j-1] + j * dp[i-1][j+1]) % MOD;
      }
      else {
        dp[i][j] = (max(0ll, j-2) * dp[i-1][j-1] + j * dp[i-1][j+1]) % MOD;
      }
    }
  }
  cout << dp[n][1] << "\n";
}

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 452 KB Output is correct
7 Correct 1 ms 468 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 452 KB Output is correct
11 Correct 1 ms 468 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 452 KB Output is correct
7 Correct 1 ms 468 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 452 KB Output is correct
11 Correct 1 ms 468 KB Output is correct
12 Correct 1 ms 1364 KB Output is correct
13 Correct 1 ms 1236 KB Output is correct
14 Correct 1 ms 1364 KB Output is correct
15 Correct 1 ms 1364 KB Output is correct
16 Correct 1 ms 1352 KB Output is correct
17 Correct 1 ms 1364 KB Output is correct
18 Correct 1 ms 1236 KB Output is correct
19 Correct 1 ms 1364 KB Output is correct
20 Correct 1 ms 1364 KB Output is correct

Subtask #4
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 452 KB Output is correct
7 Correct 1 ms 468 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 452 KB Output is correct
11 Correct 1 ms 468 KB Output is correct
12 Correct 1 ms 1364 KB Output is correct
13 Correct 1 ms 1236 KB Output is correct
14 Correct 1 ms 1364 KB Output is correct
15 Correct 1 ms 1364 KB Output is correct
16 Correct 1 ms 1352 KB Output is correct
17 Correct 1 ms 1364 KB Output is correct
18 Correct 1 ms 1236 KB Output is correct
19 Correct 1 ms 1364 KB Output is correct
20 Correct 1 ms 1364 KB Output is correct
21 Correct 3 ms 6228 KB Output is correct
22 Correct 4 ms 6852 KB Output is correct
23 Correct 4 ms 7764 KB Output is correct
24 Correct 21 ms 31940 KB Output is correct
25 Correct 19 ms 31948 KB Output is correct
26 Correct 20 ms 31940 KB Output is correct
27 Correct 21 ms 31828 KB Output is correct
28 Correct 14 ms 23776 KB Output is correct