Language: C++

g#include <iostream>
#include <cmath>
#include <cstring>
#include <deque>

using namespace std;

#define MAX_YX 10

int park[MAX_YX][MAX_YX];

int n;
int sy, sx;

int dy[] = {-2, -2, -2, -1, -1, 0, 0, 1, 1, 2, 2, 2};
int dx[] = {-1, 0, 1, -2, 2, -2, 2, -2, 2, -1, 0, 1};
bool dfs(int y, int x, int t) {
	if (t == n) {
		if ((park[y][x] >> (n-1)) & 1) return true;
		else return false;
	}
	for (int i = 0; i < 12; i++) {
		int ny = y + dy[i];
		int nx = x + dx[i];
		if (0 <= ny && ny < MAX_YX && 
		    0 <= nx && nx < MAX_YX && ((park[ny][nx] >> t) & 1)) {
			if (dfs(ny, nx, t+1)) return true;
		} 
	}
	return false;
}

int main() {
	while (cin >> sx >> sy, sx || sy) {
		cin >> n;
		memset(park, 0, sizeof(park));
		for (int i = 0; i < n; i++) {
			int spx, spy; cin >> spx >> spy;

			for (int j = spy-1; j <= spy+1; j++) {
				for (int k = spx-1; k <= spx+1; k++) {
					if (0 <= j && j < MAX_YX && 0 <= k && k < MAX_YX) {
						park[j][k] |= (1 << i);
					}
				}
			}
		}

		if (dfs(sy, sx, 0)) {
			cout << "OK" << endl;
		} else {
			cout << "NG" << endl;
		}

	}
	return 0;
}

Compiler output:
a.cc:1:2: error: stray '#' in program
    1 | g#include <iostream>
      |  ^
a.cc:1:1: error: 'g' does not name a type
    1 | g#include <iostream>
      | ^
In file included from /usr/include/c++/14/cmath:45,
                 from a.cc:2:
/usr/include/c++/14/ext/type_traits.h:164:35: error: 'constexpr const bool __gnu_cxx::__is_null_pointer' redeclared as different kind of entity
  164 |   __is_null_pointer(std::nullptr_t)
      |                                   ^
/usr/include/c++/14/ext/type_traits.h:159:5: note: previous declaration 'template<class _Type> constexpr bool __gnu_cxx::__is_null_pointer(_Type)'
  159 |     __is_null_pointer(_Type)
      |     ^~~~~~~~~~~~~~~~~
/usr/include/c++/14/ext/type_traits.h:164:26: error: 'nullptr_t' is not a member of 'std'
  164 |   __is_null_pointer(std::nullptr_t)
      |                          ^~~~~~~~~
In file included from /usr/include/c++/14/bits/stl_pair.h:60,
                 from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/bits/specfun.h:43,
                 from /usr/include/c++/14/cmath:3906:
/usr/include/c++/14/type_traits:666:33: error: 'nullptr_t' is not a member of 'std'
  666 |     struct is_null_pointer<std::nullptr_t>
      |                                 ^~~~~~~~~
/usr/include/c++/14/type_traits:666:42: error: template argument 1 is invalid
  666 |     struct is_null_pointer<std::nullptr_t>
      |                                          ^
/usr/include/c++/14/type_traits:670:48: error: template argument 1 is invalid
  670 |     struct is_null_pointer<const std::nullptr_t>
      |                                                ^
/usr/include/c++/14/type_traits:674:51: error: template argument 1 is invalid
  674 |     struct is_null_pointer<volatile std::nullptr_t>
      |                                                   ^
/usr/include/c++/14/type_traits:678:57: error: template argument 1 is invalid
  678 |     struct is_null_pointer<const volatile std::nullptr_t>
      |                                                         ^
/usr/include/c++/14/type_traits:1429:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1429 |     : public integral_constant<std::size_t, alignof(_Tp)>
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:32,
                 from /usr/include/c++/14/bits/std_abs.h:38,
                 from /usr/include/c++/14/cmath:49:
/usr/lib/gcc/x86_64-linux-gnu/14/include/stddef.h:214:23: note: 'size_t' declared here
  214 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
/usr/include/c++/14/type_traits:1429:57: error: template argument 1 is invalid
 1429 |     : public integral_constant<std::size_t, alignof(_Tp)>
      |                                                         ^
/usr/include/c++/14/type_traits:1429:57: note: invalid template non-type parameter
/usr/include/c++/14/type_traits:1438:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1438 |     : public integral_constant<std::size_t, 0> { };
      |                                     ^~~~~~
/usr/lib/gcc/x86_64-linux-gnu/14/include/stddef.h:214:23: note: 'size_t' declared here
  214 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
/usr/include/c++/14/type_traits:1438:46: error: template argument 1 is invalid
 1438 |     : public integral_constant<std::size_t, 0> { };
      |                                              ^
/usr/include/c++/14/type_traits:1438:46: note: invalid template non-type parameter
/usr/include/c++/14/type_traits:1440:26: error: 'std::size_t' has not been declared
 1440 |   template<typename _Tp, std::size_t _Size>
      |                          ^~~
/usr/include/c++/14/type_traits:1441:21: error: '_Size' was not declared in this scope
 1441 |     struct rank<_Tp[_Size]>
      |                     ^~~~~
/usr/include/c++/14/type_traits:1441:27: error: template argument 1 is invalid
 1441 |     struct rank<_Tp[_Size]>
      |                           ^
/usr/include/c++/14/type_traits:1442:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1442 |     : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
      |                                     ^~~~~~
/usr/lib/gcc/x86_64-linux-gnu/14/include/stddef.h:214:23: note: 'size_t' declared here
  214 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
/usr/include/c++/14/type_traits:1442:65: error: template argument 1 is invalid
 1442 |     : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
      |                                                                 ^
/usr/include/c++/14/type_traits:1442:65: note: invalid template non-type parameter
/usr/include/c++/14/type_traits:1446:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1446 |     : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
      |                                     ^~~~~~
/usr/lib/gcc/x86_64-linux-gnu/14/include/stddef.h:214:23: note: 'size_t' declared here
  214 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
/usr/include/c++/14/type_traits:1446:65: error: template argument 1 is invalid
 1446 |     : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
      |                                                                 ^
/usr/include/c++/14/type_traits:1446:65: note: invalid template non-type parameter
/usr/include/c++/14/type_traits:2086:26: error: 'std::size_t' has not been declared
 2086 |   template<typename _Tp, std::size_t _Size>
      |                          ^~~
/usr/include/c++/14/type_traits:2087:30: error: '_Size' was not declared in this scope
 2087 |     struct remove_extent<_Tp[_Size]>
      |                              ^~~~~
/usr/include/c++/14/type_traits:2087:36: error: template argument 1 is invalid
 2087 |     struct remove_extent<_Tp[_Size]>
      |                                    ^
/usr/include/c++/14/type_traits:2099:26: error: 'std::size_t' has not been declared
 2099 |   template<typename _Tp, std::size_t _Size>
      |                          ^~~
/usr/include/c++/14/type_traits:2100:35: error: '_Size' was not declared in this scope
 2100 |     struct remove_all_extents<_Tp[_Size]>
      |                                   ^~~~~
/usr/include/c++/14/type_traits:2100:41: error: template argument 1 is invalid
 2100 |     struct remove_all_extents<_Tp[_Size]>
      |                                         ^
/usr/include/c++/14/type_traits:2171:12: error: 'std::size_t' has not been declared
 2171 |   template<std::size_t _Len>
      |            ^~~
/usr/include/c++/14/type_traits:2176:30: error: '_Len' was not declared in this scope
 2176 |         unsigned char __data[_Len];
      |                              ^~~~
/usr/include/c++/14/type_traits:2194:12: error: 'std::size_t' has not been declared
 2194 |   template<std::size_t _Len, std::size_t _Align =
      |            ^~~
/usr/include/c++/14/type_traits:2194:30: error: 'std::size_t' has not been declared
 2194 |   template<std::size_t _Len, std::size_t _Align =
      |                              ^~~
/usr/include/c++/14/type_traits:2195:55: error: '_Len' was not declared in this scope
 2195 |            __alignof__(typename __aligned_storage_msa<_Len>::__type)>
      |                                                       ^~~~
/usr/include/c++/14/type_traits:2195:59: error: template argument 1 is invalid
 2195 |            __alignof__(typename __aligned_storage_msa<_Len>::__type)>
      |                                                           ^
/usr/include/c++/14/type_traits:2202:30: error: '_Len' was not declared in this scope
 2202 |         unsigned char __data[_Len];
      |                              ^~~~
/usr/include/c++/14/type_traits:2203:44: error: '_Align' was not declared in this scope
 2203 |         struct __attribute__((__aligned__((_Align)))) { } __align;
      |                                            ^~~~~~
In file included from /usr/include/c++/14/bits/stl_algobase.h:65:
/usr/include/c++/14/bits/stl_iterator_base_types.h:125:67: error: 'ptrdiff_t' does not name a type
  125 |   template<typename _Category, typename _Tp, typename _Distance = ptrdiff_t,
      |                                                                   ^~~~~~~~~
/usr/include/c++/14/bits/stl_iterator_base_types.h:1:1: note: 'ptrdiff_t' is defined in header '<cstddef>'; this is probably fixable by adding '#include <cstddef>'
  +++ |+#include <cstddef>
    1 | // Types used in iterator implementation -*- C++ -*-
/usr/include/c++/14/bits/stl_iterator_base_types.h:214:15: error: 'ptrdiff_t' does not name a type
  214 |       typedef ptrdiff_t                   difference_type;
      |               ^~~~~~~~~
/usr/include/c++/14/bits/stl_iterator_base_types.h:214:15: note: 'ptrdiff_t' is defined in header '<cstddef>'; this is probably fixable by adding '#include <cstddef>'
/usr/include/c++/14/bits/stl_iterator_base_types.h:225:15: error: 'ptrdiff_t' does not name a type
  225 |       typedef ptrdiff_t                   difference_type;
      |               ^~~~~~~~~
/usr/include/c++/14/bits/stl_iterator_base_types.h:225:15: note: 'ptrdiff_t' is defined in header '<cstddef>'; this is probably fixable by adding '#include <cstddef>'
In file included from /usr/include/c++/14/bits/stl_algobase.h:66:
/usr/include/c++/14/bits/stl_iterator_base_funcs.h:112:5: error: 'ptrdiff_t' does not name a type
  112 |     ptrdiff_t
      |     ^~~~~~~~~
/usr/include/c++/14/bits/stl_iterator_base_funcs.h:66:1: note: 'ptrdiff_t' is defined in header '<cstddef>'; this is probably fixable by adding '#include <cstddef>'
   65 | #include <debug/assertions.h>
  +++ |+#include <cstddef>
   66 | #include <bits/stl_iterator_base_types.h>
/usr/include/c++/14/bits/stl_iterator_base_funcs.h:118:5: error: 'ptrdiff_t' does not name a type
  118 |     ptrdiff_t
      |     ^~~~~~~~~
/usr/include/c++/14/bits/stl_iterator_base_funcs.h:118:5: note: 'ptrdiff_t' is defined in header '<cstddef>'; this is probably fixable by adding '#include <cstddef>'
In file included from /usr/include/c++/14/bits/stl_iterator.h:67,
                 from