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

//***********************
// Author:kibi11
// Quarantine Days
//***********************

#include "bits/stdc++.h"
using namespace std;
#define ll long long
#define N 100005
#define MOD 1000000007
#define dd double
#define fr(i, n) for (int i = 0; i < n; i++)
#define fr1(i, a, b) for (int i = a; i < b; i++)
#define frr(i, a, k) for (int i = a; i >= k; i--)
#define same                                                                   \\
  int t;                                                                       \\
  cin >> t;                                                                    \\
  while (t--)
#define check(x) cout << (#x) << " is " << (x) << endl;
#define pb push_back
#define mp make_pair
#define clr(x) x.clear()
#define sz(x) ((int)(x).size())
#define f first
#define s second
#define XOX
#define pi = 3.14159265358979323846

//////////////////////////////////////////////////////////////////////////
/////////////////DEBUGING ZONE//////////////////////////////

vector<string> vec_splitter(string s) {
  s += ',';
  vector<string> res;
  while (!s.empty()) {
    res.push_back(s.substr(0, s.find(',')));
    s = s.substr(s.find(',') + 1);
  }
  return res;
}
void debug_out(vector<string> __attribute__((unused)) args,
               __attribute__((unused)) int idx,
               __attribute__((unused)) int LINE_NUM) {
  cerr << endl;
}
template <typename Head, typename... Tail>
void debug_out(vector<string> args, int idx, int LINE_NUM, Head H, Tail... T) {
  if (idx > 0)
    cerr << ", ";
  else
    cerr << "Line(" << LINE_NUM << ") ";
  stringstream ss;
  ss << H;
  cerr << args[idx] << " = " << ss.str();
  debug_out(args, idx + 1, LINE_NUM, T...);
}
#ifdef XOX
#define debug(...)                                                             \\
  debug_out(vec_splitter(#__VA_ARGS__), 0, __LINE__, __VA_ARGS__)
#else
#define debug(...) 42
#endif
///////////////////////////////////////////////////////////////////////////

ll powermod(ll base, ll exp, ll mod) {
  ll result = 1;
  while (exp != 0) {
    if ((exp % 2) == 1) {
      result = (result * base) % mod;
    }
    base = (base * base) % mod;
    exp /= 2;
  }
  return result;
}

///////////////////////////////

/*
check a cycle in a directed graph: source codeforces;

void dfs(int v, int p){
  color[v] = 1; // GREY
  for(int w : g[v]){
    if(color[w] == 1){
      // you found a cycle, it's easy to recover it now.
    }
    if(color[w] == 0) dfs(w, v);
  }
  color[v] = 2; // BLACK
}
*/

///////////////////////////////////////////////////////////////////////////
// Fuctions if any:

///////////////////////////////////////////////////////////////////////////
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int tt = clock();

  int h, w;
  int sx, sy;
  int ex, ey;
  cin >> h >> w;
  cin >> sx >> sy;
  cin >> ex >> ey;
  int dir[5] = {0, 1, 0, -1, 0};
  vector<string> v;
  fr(i, h) {
    string temp;
    cin >> temp;
    v.pb(temp);
  }
  int dis[h][w];
  fr(i, h) {
    fr(j, w) {
      if (v[i][j] == '.') {
        dis[i][j] = 1e7;
      }
    }
  }
  int r, c;
  pair<int, int> temp;
  // check("bit");
  // for(auto s: dis) cout<<s.f.f<<" "<<s.f.s<<" "<<s.s<<endl;
  dis[sx - 1][sy - 1] = 0;
  deque<pair<int, int>> d;
  d.pb({sx - 1, sy - 1});
  while (!d.empty()) {
    temp = d.front();
    d.pop_front();

    fr(i, 4) {
      r = temp.f + dir[i];
      c = temp.s + dir[i + 1];
      if ((r >= 0 and c >= 0 and r < h and c < w) and v[r][c] == '.') {
        // debug()
        if (dis[r][c] > dis[temp.f][temp.s]) {
          d.push_front({r, c});
          dis[r][c] = dis[temp.f][temp.s];
        }
      }
    }
    fr1(i, -2, 3) {
      fr1(j, -2, 3) {
        r = temp.f + i;
        c = temp.s + j;
        if ((r >= 0 and c >= 0 and r < h and c < w) and v[r][c] == '.') {
          if (dis[r][c] > dis[temp.f][temp.s] + 1) {
            dis[r][c] = dis[temp.f][temp.s] + 1;
            d.pb({r, c});
          }
        }
      }
    }
  }

  // debug(dis[{ex-1,ey-1}]);
  cout << ((dis[ex - 1][ey - 1] == 1e7) ? -1 : dis[ex - 1][ey - 1]) << endl;
  // for(auto s: dis) cout<<s.f.f<<" "<<s.f.s<<" "<<s.s<<endl;
  cerr << "TIME = " << (double)1.0 * (clock() - tt) / CLOCKS_PER_SEC
       << " seconds" << endl;
  return 0;
}

Error: TLE

Fixed submission:

//***********************
// Author:kibi11
// Quarantine Days
//***********************

#include "bits/stdc++.h"
using namespace std;
#define ll long long
#define N 100005
#define MOD 1000000007
#define dd double
#define fr(i, n) for (int i = 0; i < n; i++)
#define fr1(i, a, b) for (int i = a; i < b; i++)
#define frr(i, a, k) for (int i = a; i >= k; i--)
#define same                                                                   \\
  int t;                                                                       \\
  cin >> t;                                                                    \\
  while (t--)
#define check(x) cout << (#x) << " is " << (x) << endl;
#define pb push_back
#define mp make_pair
#define clr(x) x.clear()
#define sz(x) ((int)(x).size())
#define f first
#define s second
#define XOX
#define pi = 3.14159265358979323846

//////////////////////////////////////////////////////////////////////////
/////////////////DEBUGING ZONE//////////////////////////////

vector<string> vec_splitter(string s) {
  s += ',';
  vector<string> res;
  while (!s.empty()) {
    res.push_back(s.substr(0, s.find(',')));
    s = s.substr(s.find(',') + 1);
  }
  return res;
}
void debug_out(vector<string> __attribute__((unused)) args,
               __attribute__((unused)) int idx,
               __attribute__((unused)) int LINE_NUM) {
  cerr << endl;
}
template <typename Head, typename... Tail>
void debug_out(vector<string> args, int idx, int LINE_NUM, Head H, Tail... T) {
  if (idx > 0)
    cerr << ", ";
  else
    cerr << "Line(" << LINE_NUM << ") ";
  stringstream ss;
  ss << H;
  cerr << args[idx] << " = " << ss.str();
  debug_out(args, idx + 1, LINE_NUM, T...);
}
#ifdef XOX
#define debug(...)                                                             \\
  debug_out(vec_splitter(#__VA_ARGS__), 0, __LINE__, __VA_ARGS__)
#else
#define debug(...) 42
#endif
///////////////////////////////////////////////////////////////////////////

ll powermod(ll base, ll exp, ll mod) {
  ll result = 1;
  while (exp != 0) {
    if ((exp % 2) == 1) {
      result = (result * base) % mod;
    }
    base = (base * base) % mod;
    exp /= 2;
  }
  return result;
}

///////////////////////////////

/*
check a cycle in a directed graph: source codeforces;

void dfs(int v, int p){
  color[v] = 1; // GREY
  for(int w : g[v]){
    if(color[w] == 1){
      // you found a cycle, it's easy to recover it now.
    }
    if(color[w] == 0) dfs(w, v);
  }
  color[v] = 2; // BLACK
}
*/

///////////////////////////////////////////////////////////////////////////
// Fuctions if any:

///////////////////////////////////////////////////////////////////////////
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int tt = clock();
  // ios_base& scientific (ios_base& str);

  int h, w;
  int sx, sy;
  int ex, ey;
  cin >> h >> w;
  cin >> sx >> sy;
  cin >> ex >> ey;
  int dir[5] = {0, 1, 0, -1, 0};
  vector<string> v;
  fr(i, h) {
    string temp;
    cin >> temp;
    v.pb(temp);
  }
  map<pair<int, int>, int> dis;
  fr(i, h) {
    fr(j, w) {
      if (v[i][j] == '.') {
        dis[{i, j}] = 1e7;
      }
    }
  }
  int r, c;
  pair<int, int> temp;
  // check("bit");
  // for(auto s: dis) cout<<s.f.f<<" "<<s.f.s<<" "<<s.s<<endl;
  dis[{sx - 1, sy - 1}] = 0;
  deque<pair<int, int>> d;
  d.pb({sx - 1, sy - 1});
  while (!d.empty()) {
    temp = d.front();
    d.pop_front();

    fr(i, 4) {
      r = temp.f + dir[i];
      c = temp.s + dir[i + 1];
      if ((r >= 0 and c >= 0 and r < h and c < w) and v[r][c] == '.') {
        // debug()
        if (dis[{r, c}] > dis[{temp.f, temp.s}]) {
          d.push_front({r, c});
          dis[{r, c}] = dis[{temp.f, temp.s}];
        }
      }
    }
    fr1(i, -2, 3) {
      fr1(j, -2, 3) {
        r = temp.f + i;
        c = temp.s + j;
        if ((r >= 0 and c >= 0 and r < h and c < w) and v[r][c] == '.') {
          if (dis[{r, c}] > dis[{temp.f, temp.s}] + 1) {
            dis[{r, c}] = dis[{temp.f, temp.s}] + 1;
            d.pb({r, c});
          }
        }
      }
    }
  }

  // debug(dis[{ex-1,ey-1}]);
  cout << ((dis[{ex - 1, ey - 1}] == 1e7) ? -1 : dis[{ex - 1, ey - 1}]) << endl;
  // for(auto s: dis) cout<<s.f.f<<" "<<s.f.s<<" "<<s.s<<endl;
  cerr << "TIME = " << (double)1.0 * (clock() - tt) / CLOCKS_PER_SEC
       << " seconds" << endl;
  return 0;
}