Submission #713700

#	Time	Username	Problem	Language	Result	Execution time	Memory
713700		Alex_tz307	Nautilus (BOI19_nautilus)	C++17	100 / 100	145 ms	720 KiB

nautilus

#include <bits/stdc++.h>

using namespace std;

const int kN = 500;
bitset<kN> grid[1 + kN + 1];
bitset<kN> dp[2][1 + kN + 1];

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

  int n, m, p;
  cin >> n >> m >> p;

  for (int i = 1; i <= n; ++i) {
    string s;
    cin >> s;

    for (int j = 0; j < m; ++j) {
      if (s[j] == '.') {
        grid[i][j] = 1;
      }
    }
  }

  string moves;
  cin >> moves;

  for (int i = 1; i <= n; ++i) {
    dp[0][i] = grid[i];
  }

  int t = 0;

  for (int step = 0; step < p; ++step, t ^= 1) {
    for (int i = 1; i <= n; ++i) {
      dp[t ^ 1][i].reset();

      if (moves[step] == 'N' || moves[step] == '?') {
        dp[t ^ 1][i] |= dp[t][i + 1];
      }

      if (moves[step] == 'E' || moves[step] == '?') {
        dp[t ^ 1][i] |= dp[t][i] << 1;
      }

      if (moves[step] == 'S' || moves[step] == '?') {
        dp[t ^ 1][i] |= dp[t][i - 1];
      }

      if (moves[step] == 'W' || moves[step] == '?') {
        dp[t ^ 1][i] |= dp[t][i] >> 1;
      }

      dp[t ^ 1][i] &= grid[i];
    }
  }

  int res = 0;

  for (int i = 1; i <= n; ++i) {
    res += dp[t][i].count();
  }

  cout << res << '\n';

  return 0;
}

• Subtask 1: 29 / 29
• Subtask 2: 37 / 37
• Subtask 3: 34 / 34