Language: C++

#include <bits/stdc++.h>
const int dir[4][2] = {{-1, 0}, {0, -1}, {1, 0}, {0, 1}};
const int INF = 1e9;

int h, w, k;
int x1, y1, x2, y2;
std::vector<std::vector<char>> MP;
std::vector<std::vector<int>> dis;

bool outside(int x, int y) {
	return x < 0 or x >= h or y < 0 or y >= w;
}

bool bad(int x, int y, int nd) {
	return MP[x][y] == '@' or dis[x][y] < nd;
}

void bfs() {
	std::queue<std::pair<int, int>> que;
	que.push({x1, y1});
	dis[x1][y1] = 0;
	while (!que.empty()) {
		int x = que.front().first;
		int y = que.front().second;
		que.pop();
		for (int i = 0; i < 4; i++) {
			int nx = x, ny = y;
			int nd = dis[x][y] + 1;
			for (int j = 1; j <= k; j++) {
				nx += dir[i][0];
				ny += dir[i][1];
				if (outside(nx, ny) or bad(nx, ny, nd))
					break;
				que.push({nx, ny});
				dis[nx][ny] = nd;
			}
		}
	}
}

int main() {
	std::cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
	--x1, --y1, --x2, --y2;
	MP.resize(h, std::vector<char>(w));
	dis.resize(h, std::vector<int>(w));
	for (int i = 0; i < h; i++) 
		for (int j = 0; j < w; j++)
			std::cin >> MP[i][j], dis[i][j] = INF;
	bfs();
	std::cout << (dis[x2][y2] == INF ? -1 : dis[x2][y2]);
}

Compiler output:
a.cc:6:9: error: 'int y1' redeclared as different kind of entity
    6 | int 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: In function 'void bfs()':
a.cc:20:17: error: no matching function for call to 'std::queue<std::pair<int, int> >::push(<brace-enclosed initializer list>)'
   20 |         que.push({x1, y1});
      |         ~~~~~~~~^~~~~~~~~~
In file included from /usr/include/c++/14/queue:66,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:157:
/usr/include/c++/14/bits/stl_queue.h:283:7: note: candidate: 'void std::queue<_Tp, _Sequence>::push(const value_type&) [with _Tp = std::pair<int, int>; _Sequence = std::deque<std::pair<int, int>, std::allocator<std::pair<int, int> > >; value_type = std::pair<int, int>]'
  283 |       push(const value_type& __x)
      |       ^~~~
/usr/include/c++/14/bits/stl_queue.h:283:30: note:   no known conversion for argument 1 from '<brace-enclosed initializer list>' to 'const std::queue<std::pair<int, int> >::value_type&' {aka 'const std::pair<int, int>&'}
  283 |       push(const value_type& __x)
      |            ~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_queue.h:288:7: note: candidate: 'void std::queue<_Tp, _Sequence>::push(value_type&&) [with _Tp = std::pair<int, int>; _Sequence = std::deque<std::pair<int, int>, std::allocator<std::pair<int, int> > >; value_type = std::pair<int, int>]'
  288 |       push(value_type&& __x)
      |       ^~~~
/usr/include/c++/14/bits/stl_queue.h:288:25: note:   no known conversion for argument 1 from '<brace-enclosed initializer list>' to 'std::queue<std::pair<int, int> >::value_type&&' {aka 'std::pair<int, int>&&'}
  288 |       push(value_type&& __x)
      |            ~~~~~~~~~~~~~^~~
a.cc:21:17: error: invalid conversion from 'double (*)(double) noexcept' to 'std::vector<int>::size_type' {aka 'long unsigned int'} [-fpermissive]
   21 |         dis[x1][y1] = 0;
      |                 ^~
      |                 |
      |                 double (*)(double) noexcept
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:
/usr/include/c++/14/bits/stl_vector.h:1128:28: note:   initializing argument 1 of 'std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::operator[](size_type) [with _Tp = int; _Alloc = std::allocator<int>; reference = int&; size_type = long unsigned int]'
 1128 |       operator[](size_type __n) _GLIBCXX_NOEXCEPT
      |                  ~~~~~~~~~~^~~
a.cc: In function 'int main()':
a.cc:42:39: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and 'double(double) noexcept')
   42 |         std::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:42:42: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'double (*)(double) noexcept'
   42 |         std::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:42:42: error: invalid conversion from 'double (*)(double) noexcept' to 'short int' [-fpermissive]
   42 |         std::cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
      |                                          ^~
      |                                          |
      |                                          double (*)(double) noexcept
a.cc:42:42: 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:42:42: error: invalid conversion from 'double (*)(double) noexcept' to 'short unsigned int' [-fpermissive]
   42 |         std::cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
      |                                          ^~
      |                                          |
      |                                          double (*)(double) noexcept
a.cc:42:42: 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:42:42: error: invalid conversion from 'double (*)(double) noexcept' to 'int' [-fpermissive]
   42 |         std::cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
      |                                          ^~
      |                                          |
      |                                          double (*)(double) noexcept
a.cc:42:42: 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:42:42: error: invalid conversion from 'double (*)(double) noexcept' to 'unsigned int' [-fpermissive]
   42 |         std::cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
      |                                          ^~
      |                                          |
      |                                          double (*)(double) noexcept
a.cc:42:42: 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:42:42: error: invalid conversion from 'double (*)(double) noexcept' to 'long int' [-fpermissive]
   42 |         std::cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
      |                                          ^~
      |                                          |
      |                                          double (*)(double) noexcept
a.cc:42:42: 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:42:42: error: invalid conversion from 'double (*)(double) noexcept' to 'long unsigned int' [-fpermissive]
   42 |         std::cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
      |                                          ^~
      |                                          |
      |                                          double (*)(double) noexcept
a.cc:42:42: 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:42:42: error: invalid conversion from 'double (*)(double) noexcept' to 'long long int' [-fpermissive]
   42 |         std::cin >> h >> w >> k >> x1 >> y1 >> x2 >> y2;
      |                                          ^~
      |