Problem p02579 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <bits/stdc++.h>
using namespace std;

// DEBUG BEGIN
#ifdef LOCAL
template <typename L, typename R>
ostream &operator<<(ostream &out, const pair<L, R> &p) {
  return out << "(" << p.first << ", " << p.second << ")";
}
template <typename Tuple, size_t N> struct TuplePrinter {
  static ostream &print(ostream &out, const Tuple &t) {
    return TuplePrinter<Tuple, N - 1>::print(out, t) << ", " << get<N - 1>(t);
  }
};
template <typename Tuple> struct TuplePrinter<Tuple, 1> {
  static ostream &print(ostream &out, const Tuple &t) {
    return out << get<0>(t);
  }
};
template <typename... Args>
ostream &print_tuple(ostream &out, const tuple<Args...> &t) {
  return TuplePrinter<decltype(t), sizeof...(Args)>::print(out << "(", t)
         << ")";
}
template <typename... Args>
ostream &operator<<(ostream &out, const tuple<Args...> &t) {
  return print_tuple(out, t);
}
template <typename T>
ostream &operator<<(enable_if_t<!is_same<T, string>::value, ostream> &out,
                    const T &arr) {
  out << "{";
  for (auto &x : arr)
    out << x << ", ";
  return out << (arr.size() ? "\\b\\b" : "") << "}";
}
template <size_t S> ostream &operator<<(ostream &out, const bitset<S> &b) {
  for (int i = 0; i < S; ++i)
    out << b[i];
  return out;
}
void debug_out() { cerr << "\\b\\b " << endl; }
template <typename Head, typename... Tail> void debug_out(Head H, Tail... T) {
  cerr << H << ", ", debug_out(T...);
}
void debug2_out() { cerr << "-----DEBUG END-----\\n"; }
template <typename Head, typename... Tail> void debug2_out(Head H, Tail... T) {
  cerr << "\\n";
  for (auto x : H)
    cerr << x << "\\n";
  debug2_out(T...);
}
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]: ", debug_out(__VA_ARGS__)
#define debug2(...)                                                            \\
  cerr << "----DEBUG BEGIN----\\n[" << #__VA_ARGS__ << "]:",                    \\
      debug2_out(__VA_ARGS__)
#else
#define debug(...) 42
#define debug2(...) 42
#endif
// DEBUG END

int main() {
  cin.tie(0)->sync_with_stdio(0);
  int h, w, ch, cw, dh, dw;
  cin >> h >> w >> ch >> cw >> dh >> dw, --ch, --cw, --dh, --dw;
  vector<string> a(h);
  for (auto &s : a) {
    cin >> s;
  }
  static const int inf = numeric_limits<int>::max();
  vector<vector<int>> dist(h, vector<int>(w, inf));
  dist[ch][cw] = 0;
  deque<array<int, 3>> q{{{ch, cw, 0}}};
  static const vector<pair<int, int>> dr{{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
  auto inrange = [&](int x, int y) {
    return 0 <= x && x < h && 0 <= y && y < w;
  };
  while (!q.empty()) {
    auto [x, y, d] = q.front();
    q.pop_front();
    debug(x, y, d);
    if (d == dist[x][y]) {
      for (auto [dx, dy] : dr) {
        int nx = x + dx, ny = y + dy;
        if (inrange(nx, ny) && a[nx][ny] == '.' && dist[nx][ny] > d) {
          q.push_front({nx, ny, dist[nx][ny] = d});
        }
      }
      for (auto dx = -2; dx <= 2; ++dx) {
        for (auto dy = -2; dy <= 2; ++dy) {
          int nx = x + dx, ny = y + dy;
          if (inrange(nx, ny) && a[nx][ny] == '.' && dist[nx][ny] > d + 1) {
            q.push_back({nx, ny, dist[nx][ny] = d + 1});
          }
        }
      }
    }
  }
  debug(dist);
  dist[dh][dw] < inf ? cout << dist[dh][dw] << "\\n" : cout << "-1\\n";
  return 0;
}

/*

*/

////////////////////////////////////////////////////////////////////////////////////////
//                                                                                    //
//                                   Coded by Aeren //
//                                                                                    //
////////////////////////////////////////////////////////////////////////////////////////


Error: TLE

Fixed submission:

#include <bits/stdc++.h>
using namespace std;

// DEBUG BEGIN
#ifdef LOCAL
template <typename L, typename R>
ostream &operator<<(ostream &out, const pair<L, R> &p) {
  return out << "(" << p.first << ", " << p.second << ")";
}
template <typename Tuple, size_t N> struct TuplePrinter {
  static ostream &print(ostream &out, const Tuple &t) {
    return TuplePrinter<Tuple, N - 1>::print(out, t) << ", " << get<N - 1>(t);
  }
};
template <typename Tuple> struct TuplePrinter<Tuple, 1> {
  static ostream &print(ostream &out, const Tuple &t) {
    return out << get<0>(t);
  }
};
template <typename... Args>
ostream &print_tuple(ostream &out, const tuple<Args...> &t) {
  return TuplePrinter<decltype(t), sizeof...(Args)>::print(out << "(", t)
         << ")";
}
template <typename... Args>
ostream &operator<<(ostream &out, const tuple<Args...> &t) {
  return print_tuple(out, t);
}
template <typename T>
ostream &operator<<(enable_if_t<!is_same<T, string>::value, ostream> &out,
                    const T &arr) {
  out << "{";
  for (auto &x : arr)
    out << x << ", ";
  return out << (arr.size() ? "\\b\\b" : "") << "}";
}
template <size_t S> ostream &operator<<(ostream &out, const bitset<S> &b) {
  for (int i = 0; i < S; ++i)
    out << b[i];
  return out;
}
void debug_out() { cerr << "\\b\\b " << endl; }
template <typename Head, typename... Tail> void debug_out(Head H, Tail... T) {
  cerr << H << ", ", debug_out(T...);
}
void debug2_out() { cerr << "-----DEBUG END-----\\n"; }
template <typename Head, typename... Tail> void debug2_out(Head H, Tail... T) {
  cerr << "\\n";
  for (auto x : H)
    cerr << x << "\\n";
  debug2_out(T...);
}
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]: ", debug_out(__VA_ARGS__)
#define debug2(...)                                                            \\
  cerr << "----DEBUG BEGIN----\\n[" << #__VA_ARGS__ << "]:",                    \\
      debug2_out(__VA_ARGS__)
#else
#define debug(...) 42
#define debug2(...) 42
#endif
// DEBUG END

int main() {
  cin.tie(0)->sync_with_stdio(0);
  int h, w, ch, cw, dh, dw;
  cin >> h >> w >> ch >> cw >> dh >> dw, --ch, --cw, --dh, --dw;
  vector<string> a(h);
  for (auto &s : a) {
    cin >> s;
  }
  static const int inf = numeric_limits<int>::max();
  vector<vector<int>> dist(h, vector<int>(w, inf));
  dist[ch][cw] = 0;
  deque<array<int, 3>> q{{{ch, cw, 0}}};
  static const vector<pair<int, int>> dr{{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
  auto inrange = [&](int x, int y) {
    return 0 <= x && x < h && 0 <= y && y < w;
  };
  while (!q.empty()) {
    auto [x, y, d] = q.front();
    q.pop_front();
    debug(x, y, d);
    if (d == dist[x][y]) {
      for (auto [dx, dy] : dr) {
        int nx = x + dx, ny = y + dy;
        if (inrange(nx, ny) && a[nx][ny] == '.' && dist[nx][ny] > d) {
          q.push_front({nx, ny, dist[nx][ny] = d});
        }
      }
      for (auto dx = -2; dx <= 2; ++dx) {
        for (auto dy = -2; dy <= 2; ++dy) {
          int nx = x + dx, ny = y + dy;
          if (inrange(nx, ny) && a[nx][ny] == '.' && dist[nx][ny] > d + 1) {
            q.push_front({nx, ny, dist[nx][ny] = d + 1});
          }
        }
      }
    }
  }
  debug(dist);
  dist[dh][dw] < inf ? cout << dist[dh][dw] << "\\n" : cout << "-1\\n";
  return 0;
}

/*

*/

////////////////////////////////////////////////////////////////////////////////////////
//                                                                                    //
//                                   Coded by Aeren //
//                                                                                    //
////////////////////////////////////////////////////////////////////////////////////////