Language: C++

#include<bits/stdc++.h>
#define int long long
using namespace std;
struct dq{
     int dir;
     int len;
     int x;
     int y;
};
int H, W, K, x1, y1, x2, y2;
vector<vector<int>> M;
bool valido(int x, int y){
     if(x >= 0 && x < H && y >= 0 && y < W && M[x][y]) return true;
     return false;
}
main(){
     ios_base::sync_with_stdio(false);
     cin.tie(nullptr);
     cin >> H >> W >> K >> x1 >> y1 >> x2 >> y2;
     x1--, y1--, x2--, y2--;
     M.resize(H);
     for(int i = 0; i < H; i++){
          M[i].resize(W);
          for(int j = 0; j < W; j++){
               char c; cin >> c;
               M[i][j] = ((c == '.') ? 1 : 0);
          }
     }
     int D[H][W];
     for(int i = 0; i < H; i++){
          for(int j = 0; j < W; j++)
               D[i][j] = LLONG_MAX;
     }
     D[x1][y1] = 0;
     deque<dq> q;
     q.push_back({-1, 0, x1, y1});
     while(!q.empty()){
          dq cella = q.front();
          q.pop_front();
          int dir = cella.dir;
          int len = cella.len;
          int x = cella.x;
          int y = cella.y;
          if(len == K) dir = -1;
          if(valido(x, y+1)){
               if(dir == 0){
                    if(D[x][y+1] > D[x][y]){
                         D[x][y+1] = D[x][y];
                         q.push_front({dir, len+1, x, y+1});
                    }
               }
               if(D[x][y+1] > D[x][y]+1){
                    D[x][y+1] = D[x][y]+1;
                    q.push_back({0, 1, x, y+1});
               }
          }
          if(valido(x, y-1)){
               if(dir == 1){
                    if(D[x][y-1] > D[x][y]){
                         D[x][y-1] = D[x][y];
                         q.push_front({dir, len+1, x, y-1});
                    }
               }
               if(D[x][y-1] > D[x][y]+1){
                    D[x][y-1] = D[x][y]+1;
                    q.push_back({1, 1, x, y-1});
               }
          }
          if(valido(x-1, y)){
               if(dir == 2){
                    if(D[x-1][y] > D[x][y]){
                         D[x-1][y] = D[x][y];
                         q.push_front({dir, len+1, x-1, y});
                    }
               }
               if(D[x-1][y] > D[x][y]+1){
                    D[x-1][y] = D[x][y]+1;
                    q.push_back({2, 1, x-1, y});
               }
          }
          if(valido(x+1, y)){
               if(dir == 3){
                    if(D[x+1][y] > D[x][y]){
                         D[x+1][y] = D[x][y];
                         q.push_front({dir, len+1, x+1, y});
                    }
               }
               if(D[x+1][y] > D[x][y]+1){
                    D[x+1][y] = D[x][y]+1;
                    q.push_back({3, 1, x+1, y});
               }
          }
     }
     if(D[x2][y2] == LLONG_MAX) D[x2][y2] = -1;
     cout << D[x2][y2];
}

Compiler output:
a.cc:10:18: error: 'long long int y1' redeclared as different kind of entity
   10 | int H, W, K, x1, y1, x2, y2;
      |                  ^~
In file included from /usr/include/features.h:523,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/os_defines.h:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/c++config.h:683,
                 from /usr/include/c++/14/cassert:43,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:33,
                 from a.cc:1:
/usr/include/x86_64-linux-gnu/bits/mathcalls.h:257:1: note: previous declaration 'double y1(double)'
  257 | __MATHCALL (y1,, (_Mdouble_));
      | ^~~~~~~~~~
a.cc:16:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   16 | main(){
      | ^~~~
a.cc: In function 'int main()':
a.cc:19:31: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and 'double(double) noexcept')
   19 |      cin >> H >> W >> K >> x1 >> y1 >> x2 >> y2;
      |      ~~~~~~~~~~~~~~~~~~~~~~~~ ^~ ~~
      |                         |        |
      |                         |        double(double) noexcept
      |                         std::basic_istream<char>::__istream_type {aka std::basic_istream<char>}
In file included from /usr/include/c++/14/sstream:40,
                 from /usr/include/c++/14/complex:45,
                 from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127:
/usr/include/c++/14/istream:170:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  170 |       operator>>(bool& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:170:7: note:   conversion of argument 1 would be ill-formed:
a.cc:19:34: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'double (*)(double) noexcept'
   19 |      cin >> H >> W >> K >> x1 >> y1 >> x2 >> y2;
      |                                  ^~
/usr/include/c++/14/istream:174:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  174 |       operator>>(short& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:174:7: note:   conversion of argument 1 would be ill-formed:
a.cc:19:34: error: invalid conversion from 'double (*)(double) noexcept' to 'short int' [-fpermissive]
   19 |      cin >> H >> W >> K >> x1 >> y1 >> x2 >> y2;
      |                                  ^~
      |                                  |
      |                                  double (*)(double) noexcept
a.cc:19:34: error: cannot bind rvalue '(short int)y1' to 'short int&'
/usr/include/c++/14/istream:177:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  177 |       operator>>(unsigned short& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:177:7: note:   conversion of argument 1 would be ill-formed:
a.cc:19:34: error: invalid conversion from 'double (*)(double) noexcept' to 'short unsigned int' [-fpermissive]
   19 |      cin >> H >> W >> K >> x1 >> y1 >> x2 >> y2;
      |                                  ^~
      |                                  |
      |                                  double (*)(double) noexcept
a.cc:19:34: error: cannot bind rvalue '(short unsigned int)y1' to 'short unsigned int&'
/usr/include/c++/14/istream:181:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  181 |       operator>>(int& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:181:7: note:   conversion of argument 1 would be ill-formed:
a.cc:19:34: error: invalid conversion from 'double (*)(double) noexcept' to 'int' [-fpermissive]
   19 |      cin >> H >> W >> K >> x1 >> y1 >> x2 >> y2;
      |                                  ^~
      |                                  |
      |                                  double (*)(double) noexcept
a.cc:19:34: error: cannot bind rvalue '(int)y1' to 'int&'
/usr/include/c++/14/istream:184:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  184 |       operator>>(unsigned int& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:184:7: note:   conversion of argument 1 would be ill-formed:
a.cc:19:34: error: invalid conversion from 'double (*)(double) noexcept' to 'unsigned int' [-fpermissive]
   19 |      cin >> H >> W >> K >> x1 >> y1 >> x2 >> y2;
      |                                  ^~
      |                                  |
      |                                  double (*)(double) noexcept
a.cc:19:34: error: cannot bind rvalue '(unsigned int)y1' to 'unsigned int&'
/usr/include/c++/14/istream:188:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  188 |       operator>>(long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:188:7: note:   conversion of argument 1 would be ill-formed:
a.cc:19:34: error: invalid conversion from 'double (*)(double) noexcept' to 'long int' [-fpermissive]
   19 |      cin >> H >> W >> K >> x1 >> y1 >> x2 >> y2;
      |                                  ^~
      |                                  |
      |                                  double (*)(double) noexcept
a.cc:19:34: error: cannot bind rvalue '(long int)y1' to 'long int&'
/usr/include/c++/14/istream:192:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  192 |       operator>>(unsigned long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:192:7: note:   conversion of argument 1 would be ill-formed:
a.cc:19:34: error: invalid conversion from 'double (*)(double) noexcept' to 'long unsigned int' [-fpermissive]
   19 |      cin >> H >> W >> K >> x1 >> y1 >> x2 >> y2;
      |                                  ^~
      |                                  |
      |                                  double (*)(double) noexcept
a.cc:19:34: error: cannot bind rvalue '(long unsigned int)y1' to 'long unsigned int&'
/usr/include/c++/14/istream:199:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  199 |       operator>>(long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:199:7: note:   conversion of argument 1 would be ill-formed:
a.cc:19:34: error: invalid conversion from 'double (*)(double) noexcept' to 'long long int' [-fpermissive]
   19 |      cin >> H >> W >> K >> x1 >> y1 >> x2 >> y2;
      |                                  ^~
      |                                  |
      |                                  double (*)(double) noexcept
a.cc:19:34: error: cannot bind rvalue '(long long int)y1' to 'long long int&'
/usr/include/c++/14/istream:203:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  203 |       operator>>(unsigned long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:203:7: note:   conversion of argument 1 would be ill-formed:
a.cc:19:34: error: invalid conversion from 'double (*)(double) noexcept' to 'long long unsigned int' [-fpermissive]
   19 |      cin >> H >> W >> K >> x1 >> y1 >> x2 >> y2;
      |                                  ^~
      |                                  |
      |                                  double (*)(double) noexcept
a.cc:19:34: error: cannot bind rvalue '(long long unsigned int)y1' to 'long long unsigned int&'
/usr/include/c++/14/istream:328:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  328 |       operator>>(void*& __p)
      |       ^~~~~~~~
/usr/include/c++/14/istream:328:7: note:   conversion of argument 1 would be ill-formed:
a.cc:19:34: error: invalid conversion from 'double (*)(double) noexcept' to 'void*' [-fpermissive]
   19 |      cin >> H >> W >> K >> x1 >> y1 >> x2 >> y2;
      |                                  ^~
      |                                  |
      |                                  double (*)(double) noexcept
a.cc:19:34: error: cannot bind rvalue '(void*)y1' to 'void*&'
/usr/include/c++/14/istream:122:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__istream_type& (*)(__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  122 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |       ^~~~~~~~
/usr/include/c++/14/istream:122:7: note:   conversion of argument 1 would be ill-formed:
a.cc:19:34: error: invalid conversion from 'double (*)(double) noexcept' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)' {aka 'std::basic_istream<char>& (*)(std::basic_istream<