Language: C++

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

int _main(){
    
    int h,w;
    cin >> h >> w;  
    int _sx,_sy,sx,sy;
    cin >> _sy >> _sx;  
    int _gx,_gy,gx,gy;
    cin >> _gy >> _gx;
    sx = _sx-1; sy = _sy-1;
    gx = _gx-1; gy = _gy-1;

    vector<vector<bool>> road(w, vector<bool>(h));
    for (int y=0; y<h; y++) {
        for (int x=0; x<w; x++) {
            char c;
            cin >> c;
            if(c=='.'){
                road.at(x).at(y)=true;
            }else{
                road.at(x).at(y)=false;
            }
        }
    }

    vector<vector<int>> cost(w, vector<int>(h,INFINITY));
    queue<tuple<int,int>> searchfrom;
    searchfrom.push(tuple<int,int>(sx,sy));
    int costnow = 0;
    while(true){
        queue<tuple<int,int>> searching = queue<tuple<int,int>>(searchfrom);
        vector<vector<bool>> searching_b(w, vector<int>(h,false));
        queue<tuple<int,int>> searched  = queue<tuple<int,int>>();
        searchfrom = queue<tuple<int,int>>();
        while(searching.size()>0){
            tuple<int,int> coord = searching.front();
            int cx = get<0>(coord); int cy = get<1>(coord);
            searching.pop();


            if(cx==gx && cy==gy){
                return costnow;
            }

            for(int x=max(0,cx-1); x<=min(w-1,cx+1); x++){
                for(int y=max(0,cy-1); y<=min(h-1,cy+1); y++){
                    int lenSu = abs(x-cx)+abs(y-cy);
                    if(road.at(x).at(y) && costnow<cost.at(x).at(y)){
                        if(lenSu==0){
                            cost.at(x).at(y) = costnow;
                            searched.push(tuple<int,int>(x,y));
                        }else if(lenSu==1 && !searching_b.at(x).at(y)){
                            searching.push(tuple<int,int>(x,y));
                            searching_b.at(x).at(y)=true;
                        }
                    }
                }
            }
        }
        while(searched.size()>0){
            tuple<int,int> coord = searched.front();
            int cx = get<0>(coord); int cy = get<1>(coord);
            searched.pop();

            for(int x=max(0,get<0>(coord)-2); x<=min(w-1,get<0>(coord)+2); x++){
                for(int y=max(0,get<1>(coord)-2); y<=min(h-1,get<1>(coord)+2); y++){
                    if(road.at(x).at(y) && costnow<cost.at(x).at(y)){
                        searchfrom.push(tuple<int,int>(x,y));
                    }
                }
            }
        }
        if(searchfrom.size()==0) return -1;
        costnow++;
    }
}

int main(){
    int result = _main();
    cout << result;
    return 0;
}

Compiler output:
a.cc: In function 'int _main()':
a.cc:29:47: warning: overflow in conversion from 'float' to 'std::vector<int>::value_type' {aka 'int'} changes value from '+Inff' to '2147483647' [-Woverflow]
   29 |     vector<vector<int>> cost(w, vector<int>(h,INFINITY));
      |                                               ^~~~~~~~
a.cc:35:65: error: no matching function for call to 'std::vector<std::vector<bool> >::vector(int&, std::vector<int>)'
   35 |         vector<vector<bool>> searching_b(w, vector<int>(h,false));
      |                                                                 ^
In file included from /usr/include/c++/14/vector:66,
                 from /usr/include/c++/14/functional:64,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:53,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_vector.h:707:9: note: candidate: 'template<class _InputIterator, class> std::vector<_Tp, _Alloc>::vector(_InputIterator, _InputIterator, const allocator_type&) [with <template-parameter-2-2> = _InputIterator; _Tp = std::vector<bool>; _Alloc = std::allocator<std::vector<bool> >]'
  707 |         vector(_InputIterator __first, _InputIterator __last,
      |         ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:707:9: note:   template argument deduction/substitution failed:
a.cc:35:65: note:   deduced conflicting types for parameter '_InputIterator' ('int' and 'std::vector<int>')
   35 |         vector<vector<bool>> searching_b(w, vector<int>(h,false));
      |                                                                 ^
/usr/include/c++/14/bits/stl_vector.h:678:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::initializer_list<_Tp>, const allocator_type&) [with _Tp = std::vector<bool>; _Alloc = std::allocator<std::vector<bool> >; allocator_type = std::allocator<std::vector<bool> >]'
  678 |       vector(initializer_list<value_type> __l,
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:678:43: note:   no known conversion for argument 1 from 'int' to 'std::initializer_list<std::vector<bool> >'
  678 |       vector(initializer_list<value_type> __l,
      |              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_vector.h:659:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&, std::__type_identity_t<_Alloc>&) [with _Tp = std::vector<bool>; _Alloc = std::allocator<std::vector<bool> >; std::__type_identity_t<_Alloc> = std::allocator<std::vector<bool> >]'
  659 |       vector(vector&& __rv, const __type_identity_t<allocator_type>& __m)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:659:23: note:   no known conversion for argument 1 from 'int' to 'std::vector<std::vector<bool> >&&'
  659 |       vector(vector&& __rv, const __type_identity_t<allocator_type>& __m)
      |              ~~~~~~~~~^~~~
/usr/include/c++/14/bits/stl_vector.h:640:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&, const allocator_type&, std::false_type) [with _Tp = std::vector<bool>; _Alloc = std::allocator<std::vector<bool> >; allocator_type = std::allocator<std::vector<bool> >; std::false_type = std::false_type]'
  640 |       vector(vector&& __rv, const allocator_type& __m, false_type)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:640:7: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_vector.h:635:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&, const allocator_type&, std::true_type) [with _Tp = std::vector<bool>; _Alloc = std::allocator<std::vector<bool> >; allocator_type = std::allocator<std::vector<bool> >; std::true_type = std::true_type]'
  635 |       vector(vector&& __rv, const allocator_type& __m, true_type) noexcept
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:635:7: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_vector.h:624:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(const std::vector<_Tp, _Alloc>&, std::__type_identity_t<_Alloc>&) [with _Tp = std::vector<bool>; _Alloc = std::allocator<std::vector<bool> >; std::__type_identity_t<_Alloc> = std::allocator<std::vector<bool> >]'
  624 |       vector(const vector& __x, const __type_identity_t<allocator_type>& __a)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:624:28: note:   no known conversion for argument 1 from 'int' to 'const std::vector<std::vector<bool> >&'
  624 |       vector(const vector& __x, const __type_identity_t<allocator_type>& __a)
      |              ~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_vector.h:620:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&) [with _Tp = std::vector<bool>; _Alloc = std::allocator<std::vector<bool> >]'
  620 |       vector(vector&&) noexcept = default;
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:620:7: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_vector.h:601:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(const std::vector<_Tp, _Alloc>&) [with _Tp = std::vector<bool>; _Alloc = std::allocator<std::vector<bool> >]'
  601 |       vector(const vector& __x)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:601:7: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_vector.h:569:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(size_type, const value_type&, const allocator_type&) [with _Tp = std::vector<bool>; _Alloc = std::allocator<std::vector<bool> >; size_type = long unsigned int; value_type = std::vector<bool>; allocator_type = std::allocator<std::vector<bool> >]'
  569 |       vector(size_type __n, const value_type& __value,
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:569:47: note:   no known conversion for argument 2 from 'std::vector<int>' to 'const std::vector<std::vector<bool> >::value_type&' {aka 'const std::vector<bool>&'}
  569 |       vector(size_type __n, const value_type& __value,
      |                             ~~~~~~~~~~~~~~~~~~^~~~~~~
/usr/include/c++/14/bits/stl_vector.h:556:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(size_type, const allocator_type&) [with _Tp = std::vector<bool>; _Alloc = std::allocator<std::vector<bool> >; size_type = long unsigned int; allocator_type = std::allocator<std::vector<bool> >]'
  556 |       vector(size_type __n, const allocator_type& __a = allocator_type())
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:556:51: note:   no known conversion for argument 2 from 'std::vector<int>' to 'const std::vector<std::vector<bool> >::allocator_type&' {aka 'const std::allocator<std::vector<bool> >&'}
  556 |       vector(size_type __n, const allocator_type& __a = allocator_type())
      |                             ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_vector.h:542:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(const allocator_type&) [with _Tp = std::vector<bool>; _Alloc = std::allocator<std::vector<bool> >; allocator_type = std::allocator<std::vector<bool> >]'
  542 |       vector(const allocator_type& __a) _GLIBCXX_NOEXCEPT
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:542:7: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_vector.h:531:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector() [with _Tp = std::vector<bool>; _Alloc = std::allocator<std::vector<bool> >]'
  531 |       vector() = default;
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:531:7: note:   candidate expects 0 arguments, 2 provided