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Submission #813891

# Submission time Handle Problem Language Result Execution time Memory
813891 2023-08-08T04:26:18 Z devariaota Tents (JOI18_tents) C++17
100 / 100
 170 ms 70856 KB 
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

const int MX = 3005, mod = 1e9 + 7, inv = 5e8 + 4;

int H, W;
ll dp[MX][MX];

int main() {
      cin.tie(0); ios_base::sync_with_stdio(0);

      cin >> H >> W;

      dp[0][W] = 1;

      for(int i = 0; i < H; i++) {
            for(int a = 0; a <= W; a++) { 
                  dp[i + 1][a] += dp[i][a];
                  dp[i + 1][a] %= mod;

                  if(a - 1 >= 0) {
                        dp[i + 1][a - 1] += 1LL * dp[i][a] * a * 4 % mod;
                        dp[i + 1][a - 1] %= mod;
                  }

                  if(a - 2 >= 0) {
                        dp[i + 1][a - 2] += 1LL * dp[i][a] * a % mod * (a - 1) % mod * inv % mod;
                        dp[i + 1][a - 2] %= mod;
                  }

                  if(i + 2 <= H && a - 1 >= 0) {
                        dp[i + 2][a - 1] += 1LL * dp[i][a] * (H - i - 1) % mod * a % mod;
                        dp[i + 2][a - 1] %= mod;
                  }
            }
      }


      ll ans = 0;
      for(int a = 0; a < W; a++) {
            ans += dp[H][a];
            ans %= mod;
      }

      cout << ans << '\n';
      
}

Subtask #1
48.0 / 48.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 468 KB Output is correct
4 Correct 1 ms 1108 KB Output is correct
5 Correct 1 ms 596 KB Output is correct
6 Correct 1 ms 1364 KB Output is correct
7 Correct 1 ms 724 KB Output is correct
8 Correct 1 ms 1364 KB Output is correct
9 Correct 1 ms 724 KB Output is correct
10 Correct 2 ms 1748 KB Output is correct
11 Correct 0 ms 340 KB Output is correct
12 Correct 3 ms 2216 KB Output is correct

Subtask #2
52.0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 468 KB Output is correct
4 Correct 1 ms 1108 KB Output is correct
5 Correct 1 ms 596 KB Output is correct
6 Correct 1 ms 1364 KB Output is correct
7 Correct 1 ms 724 KB Output is correct
8 Correct 1 ms 1364 KB Output is correct
9 Correct 1 ms 724 KB Output is correct
10 Correct 2 ms 1748 KB Output is correct
11 Correct 0 ms 340 KB Output is correct
12 Correct 3 ms 2216 KB Output is correct
13 Correct 0 ms 340 KB Output is correct
14 Correct 5 ms 9556 KB Output is correct
15 Correct 113 ms 55176 KB Output is correct
16 Correct 8 ms 4044 KB Output is correct
17 Correct 26 ms 12860 KB Output is correct
18 Correct 32 ms 16980 KB Output is correct
19 Correct 128 ms 62912 KB Output is correct
20 Correct 105 ms 50828 KB Output is correct
21 Correct 75 ms 33824 KB Output is correct
22 Correct 70 ms 35468 KB Output is correct
23 Correct 43 ms 26992 KB Output is correct
24 Correct 170 ms 70856 KB Output is correct
25 Correct 130 ms 61204 KB Output is correct
26 Correct 162 ms 66572 KB Output is correct
27 Correct 163 ms 69008 KB Output is correct