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

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

#define ll long long
#define X first
#define Y second
#define all(x) x.begin(), x.end()
#define ordered_set                                                            \\
  tree<int, null_type, less<int>, rb_tree_tag,                                 \\
       tree_order_statistics_node_update>

#define sim template <class c
#define ris return *this
#define dor > debug &operator<<
#define eni(x)                                                                 \\
  sim > typename enable_if<sizeof dud<c>(0) x 1, debug &>::type operator<<(    \\
            c i) {
sim > struct rge {
  c b, e;
};
sim > rge<c> range(c i, c j) { return rge<c>{i, j}; }
sim > auto dud(c *x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug {
#ifdef LOCAL
  ~debug() { cerr << endl; }
  eni(!=) cerr << boolalpha << i;
  ris;
} eni(==) ris << range(begin(i), end(i));
}
sim, class b dor(pair<b, c> d) {
  ris << "(" << d.first << ", " << d.second << ")";
}
sim dor(rge<c> d) {
  *this << "[";
  for (auto it = d.b; it != d.e; ++it)
    *this << ", " + 2 * (it == d.b) << *it;
  ris << "]";
}
#else
  sim dor(const c &) { ris; }
#endif
}
;
#define imie(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "

const int MOD = (int)1e9 + 7;
const int MX = (int)1e5 + 10;

void add_self(int &x, int y, int md = MOD) {
  x += y;
  if (x >= md)
    x -= md;
}
void sub_self(int &x, int y, int md = MOD) {
  x -= y;
  if (x < 0)
    x += md;
}
void mul_self(int &x, int y, int md = MOD) { x = x * 1LL * y % md; }
inline int mul(int x, int y, int md = MOD) { return x * 1LL * y % md; }
inline int add(int x, int y, int md = MOD) {
  x += y;
  if (x >= md)
    x -= md;
  return x;
}
inline int sub(int x, int y, int md = MOD) {
  x -= y;
  if (x < 0)
    x += md;
  return x;
}

const int dx[] = {0, 0, -1, 1};
const int dy[] = {1, -1, 0, 0};

void pre() {}

void solve() {
  int h, w, srcx, srcy, desx, desy;
  cin >> h >> w >> srcx >> srcy >> desx >> desy;
  --srcx, --srcy, --desx, --desy;
  vector<vector<char>> vec(h, vector<char>(w));
  for (auto &rw : vec)
    for (auto &c : rw)
      cin >> c;

  auto ok = [&](int xx, int yy) {
    return xx >= 0 && xx < h && yy >= 0 && yy < w && vec[xx][yy] != '#';
  };

  vector<vector<int>> dist(h, vector<int>(w, 1e9));
  dist[srcx][srcy] = 0;
  deque<array<int, 2>> q;
  q.push_front({srcx, srcy});

  while (!q.empty()) {
    auto p = q.front();
    q.pop_front();
    for (int i = 0; i < 4; ++i) {
      int xx = p[0] + dx[i];
      int yy = p[1] + dy[i];
      if (ok(xx, yy) && dist[xx][yy] > dist[p[0]][p[1]]) {
        dist[xx][yy] = dist[p[0]][p[1]];
        q.push_front({xx, yy});
      }
    }
    for (int i = -2; i <= 2; ++i) {
      for (int j = -2; j <= 2; ++j) {
        int xx = p[0] + i;
        int yy = p[1] + j;
        if (ok(xx, yy) && dist[xx][yy] > dist[p[0]][p[1]] + 1) {
          dist[xx][yy] = dist[p[0]][p[1]] + 1;
          q.push_back({xx, yy});
        }
      }
    }
  }

  int res = dist[desx][desy];
  if (res == (int)1e9)
    res = -1;
  cout << res << "\\n";

  return;
}

int main() {

  cin.tie(0);
  cout.tie(0);
  ios_base::sync_with_stdio(0);

  // freopen("input.in", "r", stdin);
  // freopen("output.out", "w", stdout);

  int t;
  t = 1;
  // cin >> t;
  // pre();
  for (int i = 1; i <= t; ++i) {
    // cout << "Case #" << i << ": ";
    solve();
    // cout << '\\n';
    // cout << endl;
  }

  return 0;
}


Error: TLE

Fixed submission:

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

#define ll long long
#define X first
#define Y second
#define all(x) x.begin(), x.end()
#define ordered_set                                                            \\
  tree<int, null_type, less<int>, rb_tree_tag,                                 \\
       tree_order_statistics_node_update>

#define sim template <class c
#define ris return *this
#define dor > debug &operator<<
#define eni(x)                                                                 \\
  sim > typename enable_if<sizeof dud<c>(0) x 1, debug &>::type operator<<(    \\
            c i) {
sim > struct rge {
  c b, e;
};
sim > rge<c> range(c i, c j) { return rge<c>{i, j}; }
sim > auto dud(c *x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug {
#ifdef LOCAL
  ~debug() { cerr << endl; }
  eni(!=) cerr << boolalpha << i;
  ris;
} eni(==) ris << range(begin(i), end(i));
}
sim, class b dor(pair<b, c> d) {
  ris << "(" << d.first << ", " << d.second << ")";
}
sim dor(rge<c> d) {
  *this << "[";
  for (auto it = d.b; it != d.e; ++it)
    *this << ", " + 2 * (it == d.b) << *it;
  ris << "]";
}
#else
  sim dor(const c &) { ris; }
#endif
}
;
#define imie(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "

const int MOD = (int)1e9 + 7;
const int MX = (int)1e5 + 10;

void add_self(int &x, int y, int md = MOD) {
  x += y;
  if (x >= md)
    x -= md;
}
void sub_self(int &x, int y, int md = MOD) {
  x -= y;
  if (x < 0)
    x += md;
}
void mul_self(int &x, int y, int md = MOD) { x = x * 1LL * y % md; }
inline int mul(int x, int y, int md = MOD) { return x * 1LL * y % md; }
inline int add(int x, int y, int md = MOD) {
  x += y;
  if (x >= md)
    x -= md;
  return x;
}
inline int sub(int x, int y, int md = MOD) {
  x -= y;
  if (x < 0)
    x += md;
  return x;
}

const int dx[] = {0, 0, -1, 1};
const int dy[] = {1, -1, 0, 0};

void pre() {}

void solve() {
  int h, w, srcx, srcy, desx, desy;
  cin >> h >> w >> srcx >> srcy >> desx >> desy;
  --srcx, --srcy, --desx, --desy;
  vector<vector<char>> vec(h, vector<char>(w));
  for (auto &rw : vec)
    for (auto &c : rw)
      cin >> c;

  auto ok = [&](int xx, int yy) {
    return xx >= 0 && xx < h && yy >= 0 && yy < w && vec[xx][yy] != '#';
  };

  vector<vector<int>> dist(h, vector<int>(w, 1e9));
  dist[srcx][srcy] = 0;
  queue<array<int, 2>> q;
  q.push({srcx, srcy});
  while (!q.empty()) {
    auto p = q.front();
    q.pop();
    for (int i = 0; i < 4; ++i) {
      int xx = p[0] + dx[i];
      int yy = p[1] + dy[i];
      if (ok(xx, yy) && dist[xx][yy] > dist[p[0]][p[1]]) {
        dist[xx][yy] = dist[p[0]][p[1]];
        q.push({xx, yy});
      }
    }
    for (int i = -2; i <= 2; ++i) {
      for (int j = -2; j <= 2; ++j) {
        int xx = p[0] + i;
        int yy = p[1] + j;
        if (ok(xx, yy) && dist[xx][yy] > dist[p[0]][p[1]] + 1) {
          dist[xx][yy] = dist[p[0]][p[1]] + 1;
          q.push({xx, yy});
        }
      }
    }
  }

  int res = dist[desx][desy];
  if (res == (int)1e9)
    res = -1;
  cout << res << "\\n";

  return;
}

int main() {

  cin.tie(0);
  cout.tie(0);
  ios_base::sync_with_stdio(0);

  // freopen("input.in", "r", stdin);
  // freopen("output.out", "w", stdout);

  int t;
  t = 1;
  // cin >> t;
  // pre();
  for (int i = 1; i <= t; ++i) {
    // cout << "Case #" << i << ": ";
    solve();
    // cout << '\\n';
    // cout << endl;
  }

  return 0;
}