Language: C++

clude <bits/stdc++.h>
 
#define rep2(x,fr,to) for(int x=(fr);x<(to);x++)
#define rep(x,to) for(int x=0;x<(to);x++)
#define repr(x,fr,to) for(int x=(fr);x>=(to);x--)
#define all(c) c.begin(),c.end()
#define sz(v) (int)v.size()
 
using namespace std;
typedef long long  ll; typedef vector<int> VI; typedef pair<int,int> pii; typedef vector<ll> VL; const int MD = 1e9 + 7;
void dbg(){cerr<<"\n";} template <class F,class ...S> void dbg(const F& f, const S&...s){cerr <<f <<": "; dbg(s...);}
 
int main()
{
	cin.tie(0); ios_base::sync_with_stdio(false);
	int h,w, ch,cw, dh, dw;
	cin >>h >>w >>ch >>cw >>dh >>dw;
	vector<string> ba(h);
	rep(i, h) cin >>ba[i];
	ch--;cw--;dh--;dw--;
	
	const int dr[]={0,1,0,-1,0};
	typedef tuple<ll, int, int> pli;
	const ll INF = 1e18;
	priority_queue< pli, vector<pli>, greater<pli> > que;
	vector<VL> d(h, VL(w, INF));
	d[ch][cw] = 0;
	que.emplace(0, ch, cw);
	while(!que.empty()){
		auto [cost, cy, cx ] = que.top(); que.pop();
		if(d[cy][cx] < cost) continue;
 
		rep(i, 4){
			int ny = cy+dr[i], nx=cx+dr[i+1];
			if(ny<0 || ny>=h || nx<0 || nx>=w || ba[ny][nx] !='.') continue;
			ll ncst = d[cy][cx];
			if(d[ny][nx]> ncst){
				d[ny][nx] = ncst; que.emplace(ncst, ny, nx);
			}
		}
		rep2(yy, -2,3) rep2(xx, -2,3){
			int ny = cy+yy, nx=cx+xx;
			if(ny<0 || ny>=h || nx<0 || nx>=w || ba[ny][nx] !='.') continue;
			ll ncst = d[cy][cx] + 1;
			if(d[ny][nx] > ncst){
				d[ny][nx] = ncst; que.emplace(ncst, ny, nx);
			}
		}
	}
 
	ll ans = d[dh][dw];
	cout << (ans!=INF? ans: -1) <<"\n";
	return 0;
}

Compiler output:
a.cc:1:1: error: 'clude' does not name a type
    1 | clude <bits/stdc++.h>
      | ^~~~~
a.cc:10:32: error: 'vector' does not name a type
   10 | typedef long long  ll; typedef vector<int> VI; typedef pair<int,int> pii; typedef vector<ll> VL; const int MD = 1e9 + 7;
      |                                ^~~~~~
a.cc:10:56: error: 'pair' does not name a type
   10 | typedef long long  ll; typedef vector<int> VI; typedef pair<int,int> pii; typedef vector<ll> VL; const int MD = 1e9 + 7;
      |                                                        ^~~~
a.cc:10:83: error: 'vector' does not name a type
   10 | typedef long long  ll; typedef vector<int> VI; typedef pair<int,int> pii; typedef vector<ll> VL; const int MD = 1e9 + 7;
      |                                                                                   ^~~~~~
a.cc: In function 'void dbg()':
a.cc:11:12: error: 'cerr' was not declared in this scope
   11 | void dbg(){cerr<<"\n";} template <class F,class ...S> void dbg(const F& f, const S&...s){cerr <<f <<": "; dbg(s...);}
      |            ^~~~
a.cc: In function 'void dbg(const F&, const S& ...)':
a.cc:11:90: error: 'cerr' was not declared in this scope
   11 | void dbg(){cerr<<"\n";} template <class F,class ...S> void dbg(const F& f, const S&...s){cerr <<f <<": "; dbg(s...);}
      |                                                                                          ^~~~
a.cc: In function 'int main()':
a.cc:15:9: error: 'cin' was not declared in this scope
   15 |         cin.tie(0); ios_base::sync_with_stdio(false);
      |         ^~~
a.cc:15:21: error: 'ios_base' has not been declared
   15 |         cin.tie(0); ios_base::sync_with_stdio(false);
      |                     ^~~~~~~~
a.cc:18:9: error: 'vector' was not declared in this scope
   18 |         vector<string> ba(h);
      |         ^~~~~~
a.cc:18:16: error: 'string' was not declared in this scope
   18 |         vector<string> ba(h);
      |                ^~~~~~
a.cc:18:24: error: 'ba' was not declared in this scope
   18 |         vector<string> ba(h);
      |                        ^~
a.cc:23:17: error: 'tuple' does not name a type
   23 |         typedef tuple<ll, int, int> pli;
      |                 ^~~~~
a.cc:25:9: error: 'priority_queue' was not declared in this scope
   25 |         priority_queue< pli, vector<pli>, greater<pli> > que;
      |         ^~~~~~~~~~~~~~
a.cc:25:25: error: 'pli' was not declared in this scope
   25 |         priority_queue< pli, vector<pli>, greater<pli> > que;
      |                         ^~~
a.cc:25:41: error: expected primary-expression before ',' token
   25 |         priority_queue< pli, vector<pli>, greater<pli> > que;
      |                                         ^
a.cc:25:43: error: 'greater' was not declared in this scope
   25 |         priority_queue< pli, vector<pli>, greater<pli> > que;
      |                                           ^~~~~~~
a.cc:25:56: error: expected primary-expression before '>' token
   25 |         priority_queue< pli, vector<pli>, greater<pli> > que;
      |                                                        ^
a.cc:25:58: error: 'que' was not declared in this scope
   25 |         priority_queue< pli, vector<pli>, greater<pli> > que;
      |                                                          ^~~
a.cc:26:16: error: 'VL' was not declared in this scope
   26 |         vector<VL> d(h, VL(w, INF));
      |                ^~
a.cc:26:20: error: 'd' was not declared in this scope; did you mean 'dr'?
   26 |         vector<VL> d(h, VL(w, INF));
      |                    ^
      |                    dr
a.cc:35:45: error: 'nx' was not declared in this scope; did you mean 'ny'?
   35 |                         if(ny<0 || ny>=h || nx<0 || nx>=w || ba[ny][nx] !='.') continue;
      |                                             ^~
      |                                             ny
a.cc:37:34: error: 'nx' was not declared in this scope; did you mean 'ny'?
   37 |                         if(d[ny][nx]> ncst){
      |                                  ^~
      |                                  ny
a.cc:43:45: error: 'nx' was not declared in this scope; did you mean 'ny'?
   43 |                         if(ny<0 || ny>=h || nx<0 || nx>=w || ba[ny][nx] !='.') continue;
      |                                             ^~
      |                                             ny
a.cc:45:34: error: 'nx' was not declared in this scope; did you mean 'ny'?
   45 |                         if(d[ny][nx] > ncst){
      |                                  ^~
      |                                  ny
a.cc:52:9: error: 'cout' was not declared in this scope
   52 |         cout << (ans!=INF? ans: -1) <<"\n";
      |         ^~~~