Language: C++

#include <bits/stdc++.h>

using namespace std;

int mp[1005000],dist[1005000];
int h,w,k;
int x1,x2,y1,y2;

int get(int x,int y)
{
	return (x - 1) * w + y;
}

int getx(int id)
{
	return (id - 1) / w + 1;
}

int gety(int id)
{
	return id % w == 0 ? w : id % w;
}

char str[1005000];

int main()
{
	scanf("%d%d%d",&h,&w,&k);
	scanf("%d%d%d%d",&x1,&y1,&x2,&y2);
	for(int i = 1;i <= h; ++ i)
	{
		scanf("%s",str + 1);
		for(int j = 1;j <= w; ++ j)
			mp[get(i,j)] = str[j] == '@' ? 0 : 1;
	}
	if(!mp[get(x1,y1)] || !mp[get(x2,y2)])
	{
		puts("-1\n");
		return 0;
	}
	memset(dist,-1,sizeof(dist));
	dist[get(x1,y1)] = 0;
	queue<int> que; que.push(get(x1,y1));
	while(!que.empty())
	{
		int u = que.front();
		int xx = getx(u),yy = gety(u);
		que.pop();
		bool fg1 = 1,fg2 = 1,fg3 = 1,fg4 = 1;
		int td = dist[get(xx,yy)] + 1;
		for(int i = 1;i <= k; ++ i)
		{
			if(xx + i <= h && fg1)
			{
				if(mp[get(xx + i,yy)] && (dist[get(xx + i,yy)] == -1 || dist[get(xx + i,yy)] == td))
				{
					if(dist[get(xx - i,yy)] != td)
						que.push(get(xx - i,yy));
					dist[get(xx + i,yy)] = td;
				}
				else fg1 = 0;
			}
			else fg1 = 0;
			if(xx - i > 0 && fg2)
			{
				if(mp[get(xx - i,yy)] && (dist[get(xx - i,yy)] == -1 || dist[get(xx - i,yy)] == td))
				{
					if(dist[get(xx - i,yy)] != td)
						que.push(get(xx - i,yy));
					dist[get(xx - i,yy)] = td;
				}
				else fg2 = 0;
			}
			else fg2 = 0;
			if(yy + i <= w && fg3)
			{
				if(mp[get(xx,yy + i)] && (dist[get(xx,yy + i)] == -1 || dist[get(xx,yy + i)] == td))
				{
					if(dist[get(xx,yy + i)] != td)
						que.push(get(xx,yy + i));
					dist[get(xx,yy + i)] = td;
				}
				else fg3 = 0;
			}
			else fg3 = 0;
			if(yy - i > 0 && fg4)
			{
				if(mp[get(xx,yy - i)] && (dist[get(xx,yy - i)] == -1 || dist[get(xx,yy - i)] == td))
				{
					if(dist[get(xx,yy - i)] != td)
						que.push(get(xx,yy - i));
					dist[get(xx,yy - i)] = dist[get(xx,yy)] + 1;
				}
				else fg4 = 0;
			}
			else fg4 = 0;
			if(!fg1 && !fg2 && !fg3 && !fg4) break;
		}
	}
	printf("%d\n",dist[get(x2,y2)]);
}

Compiler output:
a.cc:7:11: error: 'int y1' redeclared as different kind of entity
    7 | int x1,x2,y1,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 'int main()':
a.cc:36:19: error: no matching function for call to 'get(int&, double (&)(double) noexcept)'
   36 |         if(!mp[get(x1,y1)] || !mp[get(x2,y2)])
      |                ~~~^~~~~~~
a.cc:9:5: note: candidate: 'int get(int, int)' (near match)
    9 | int get(int x,int y)
      |     ^~~
a.cc:9:5: note:   conversion of argument 2 would be ill-formed:
a.cc:36:23: error: invalid conversion from 'double (*)(double) noexcept' to 'int' [-fpermissive]
   36 |         if(!mp[get(x1,y1)] || !mp[get(x2,y2)])
      |                       ^~
      |                       |
      |                       double (*)(double) noexcept
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51:
/usr/include/c++/14/bits/stl_pair.h:1250:5: note: candidate: 'template<long unsigned int _Int, class _Tp1, class _Tp2> constexpr typename std::tuple_element<_Int, std::pair<_Tp1, _Tp2> >::type& std::get(pair<_Tp1, _Tp2>&)'
 1250 |     get(pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1250:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_pair.h:1255:5: note: candidate: 'template<long unsigned int _Int, class _Tp1, class _Tp2> constexpr typename std::tuple_element<_Int, std::pair<_Tp1, _Tp2> >::type&& std::get(pair<_Tp1, _Tp2>&&)'
 1255 |     get(pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1255:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_pair.h:1260:5: note: candidate: 'template<long unsigned int _Int, class _Tp1, class _Tp2> constexpr const typename std::tuple_element<_Int, std::pair<_Tp1, _Tp2> >::type& std::get(const pair<_Tp1, _Tp2>&)'
 1260 |     get(const pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1260:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_pair.h:1265:5: note: candidate: 'template<long unsigned int _Int, class _Tp1, class _Tp2> constexpr const typename std::tuple_element<_Int, std::pair<_Tp1, _Tp2> >::type&& std::get(const pair<_Tp1, _Tp2>&&)'
 1265 |     get(const pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1265:5: note:   candidate expects 1 argument, 2 provided
In file included from /usr/include/c++/14/bits/memory_resource.h:47,
                 from /usr/include/c++/14/string:68,
                 from /usr/include/c++/14/bitset:52,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:52:
/usr/include/c++/14/tuple:2445:5: note: candidate: 'template<long unsigned int __i, class ... _Elements> constexpr std::__tuple_element_t<__i, std::tuple<_Elements ...> >& std::get(tuple<_Elements ...>&)'
 2445 |     get(tuple<_Elements...>& __t) noexcept
      |     ^~~
/usr/include/c++/14/tuple:2445:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/tuple:2451:5: note: candidate: 'template<long unsigned int __i, class ... _Elements> constexpr std::__tuple_element_t<__i, std::tuple<_Elements ...> >& std::get(const tuple<_Elements ...>&)'
 2451 |     get(const tuple<_Elements...>& __t) noexcept
      |     ^~~
/usr/include/c++/14/tuple:2451:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/tuple:2457:5: note: candidate: 'template<long unsigned int __i, class ... _Elements> constexpr std::__tuple_element_t<__i, std::tuple<_Elements ...> >&& std::get(tuple<_Elements ...>&&)'
 2457 |     get(tuple<_Elements...>&& __t) noexcept
      |     ^~~
/usr/include/c++/14/tuple:2457:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/tuple:2466:5: note: candidate: 'template<long unsigned int __i, class ... _Elements> constexpr std::__tuple_element_t<__i, std::tuple<_Elements ...> >&& std::get(const tuple<_Elements ...>&&)'
 2466 |     get(const tuple<_Elements...>&& __t) noexcept
      |     ^~~
/usr/include/c++/14/tuple:2466:5: note:   candidate expects 1 argument, 2 provided
In file included from /usr/include/c++/14/functional:65,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:53:
/usr/include/c++/14/array:390:5: note: candidate: 'template<long unsigned int _Int, class _Tp, long unsigned int _Nm> constexpr _Tp& std::get(array<_Tp, _Nm>&)'
  390 |     get(array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/14/array:390:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/array:399:5: note: candidate: 'template<long unsigned int _Int, class _Tp, long unsigned int _Nm> constexpr _Tp&& std::get(array<_Tp, _Nm>&&)'
  399 |     get(array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/14/array:399:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/array:408:5: note: candidate: 'template<long unsigned int _Int, class _Tp, long unsigned int _Nm> constexpr const _Tp& std::get(const array<_Tp, _Nm>&)'
  408 |     get(const array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/14/array:408:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/array:417:5: note: candidate: 'template<long unsigned int _Int, class _Tp, long unsigned int _Nm> constexpr const _Tp&& std::get(const array<_Tp, _Nm>&&)'
  417 |     get(const array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/14/array:417:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_pair.h:1272:5: note: candidate: 'template<class _Tp, class _Up> constexpr _Tp& std::get(pair<_T1, _T2>&)'
 1272 |     get(pair<_Tp, _Up>& __p) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1272:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_pair.h:1277:5: note: candidate: 'template<class _Tp, class _Up> constexpr const _Tp& std::get(const pair<_T1, _T2>&)'
 1277 |     get(const pair<_Tp, _Up>& __p) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1277:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_pair.h:1282:5: note: candidate: 'template<class _Tp, class _Up> constexpr _Tp&& std::get(pair<_T1, _T2>&&)'
 1282 |     get(pair<_Tp, _Up>&& __p) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1282:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_pair.h:1287:5: note: candidate: 'template<class _Tp, class _Up> constexpr const _Tp&& std::get(const pair<_T1, _T2>&&)'
 1287 |     get(const pair<_Tp, _Up>&& __p) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1287:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_pair.h:1292:5: note: candidate: 'template<class _Tp, class _Up> constexpr _Tp& std::get(pair<_Up, _Tp>&)'
 1292 |     get(pair<_Up, _Tp>& __p) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1292:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_pair.h:1297:5: note: candidate: 'template<class _Tp, class _Up> constexpr const _Tp& std::get(const pair<_Up, _Tp>&)'
 1297 |     get(const pair<_Up, _Tp>& __p) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1297:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_pair.h:1302:5: note: candidate: 'template<class _Tp, class _Up> constexpr _Tp&& std::get(pair<_Up, _Tp>&&)'
 1302 |     get(pair<_Up, _Tp>&& __p) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1302:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_pair.h:1307:5: note: candidate: 'template<class _Tp, class _Up> constexpr const _Tp&& std::get(const pair<_Up, _Tp>&&)'
 1307 |     get(const pair<_Up, _Tp>&& __p) noexcept
      |     ^~~
/usr/include/c++/14/bits/stl_pair.h:1307:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/tuple:2476:5: note: candidate: 'template<long unsigned int __i, class ... _Elements> constexpr std::__enable_if_t<(__i >= sizeof... (_Types))> std::get(const tuple<_Elements ...>&)' (deleted)
 2476 |     get(const tuple<_Elements...>&) = delete;
      |     ^~~
/usr/include/c++/14/tuple:2476:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/tuple:2483:5: note: candidate: 'template<class _Tp, class ... _Types> constexpr _Tp& std::get(tuple<_Elements ...>&)'
 2483 |     get(tuple<_Types...>& __t) noexcept
      |     ^~~
/usr/include/c++/14/tuple:2483:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/tuple:2494:5: note: candidate: 'template<class _Tp, class ... _Types> constexpr _Tp&& std::get(tuple<_Elements ...>&&)'
 2494 |     get(tuple<_Types...>&& __t) noexcept
      |     ^~~
/usr/include/c++/14/tuple:2494:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/tuple:2505:5: note: candidate: 'template<class _Tp, class ... _Types> constexpr const _Tp& std::get(const tuple<_Elements ...>&)'
 2505 |     get(const tuple<_Types...>& __t) noexcept
      |     ^~~
/usr/include/c++/14/tuple:2505:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/tuple:2517:5: note: candidate: 'template<class _Tp, class ... _Types> constexpr const _Tp&& std::get(const tuple<_Elements ...>&&)'
 2517 |     get(const tuple<_Types...>&& __t) noexcept
      |     ^~~
/usr/include/c++/14/tuple:2517:5: note:   candidate expects 1 argument, 2 provided
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:80:
/usr/include/c++/14/variant:1715:5: