Language: C++

#include <iostream>
#include <queue>
#include <map>
#include <string>

using namespace std;

const int dx[][4] = {{1, 0, -1, 0}, {-1, 0, 1, 0}};
const int dy[][4] = {{0, 1, 0, -1}, {0, -1, 0, 1}};

int X, Y;

bool map[50][50];
bool passed[50][50][50][50];

struct P
{
    int tx, ty;
    int kx, ky;
    int cost;

    P(int _tx, int _ty, int _kx, int _ky, int _cost) : tx(_tx), ty(_ty), kx(_kx), ky(_ky), cost(_cost) {};
};

bool check(int x, int y)
{
    return x < 0 || x >= X || y < 0 || y >= Y || map[y][x];
}

int main()
{
    int tx, ty, kx, ky, ans;
    while(cin >> X >> Y, X|Y)
    {
        ans = -1;
        memset(passed, 0, sizeof passed);
        queue<P> que;

        cin >> tx >> ty >> kx >> ky;
        tx--, ty--, kx--, ky--;

        for(int i = 0; i < Y; i++)
            for(int j = 0; j < X; j++)
                cin >> map[i][j];

        passed[tx][ty][kx][ky] = true;

        for(que.push(P(tx, ty, kx, ky, 0)); !que.empty(); que.pop())
        {
            P p = que.front();

            if(p.cost >= 100)
                break;

            if(p.tx == p.kx && p.ty == p.ky)
            {
                ans = p.cost;
                break;
            }

            for(int i = 0; i < 4; i++)
            {
                int mtx = p.tx + dx[0][i], mty = p.ty + dy[0][i];
                int mkx = p.kx + dx[1][i], mky = p.ky + dy[1][i];

                if(check(mtx, mty))
                    mtx = p.tx, mty = p.ty;
                if(check(mkx, mky))
                    mkx = p.kx, mky = p.ky;
                if(passed[mtx][mty][mkx][mky])
                    continue;

                passed[mtx][mty][mkx][mky] = true;
                que.push(P(mtx, mty, mkx, mky, p.cost + 1));
            }
        }

        if(ans == -1)
            puts("NA");
        else
            cout << ans << endl;
    }
}


Compiler output:
a.cc: In function 'bool check(int, int)':
a.cc:27:50: error: reference to 'map' is ambiguous
   27 |     return x < 0 || x >= X || y < 0 || y >= Y || map[y][x];
      |                                                  ^~~
In file included from /usr/include/c++/14/map:63,
                 from a.cc:3:
/usr/include/c++/14/bits/stl_map.h:102:11: note: candidates are: 'template<class _Key, class _Tp, class _Compare, class _Alloc> class std::map'
  102 |     class map
      |           ^~~
a.cc:13:6: note:                 'bool map [50][50]'
   13 | bool map[50][50];
      |      ^~~
a.cc: In function 'int main()':
a.cc:36:9: error: 'memset' was not declared in this scope
   36 |         memset(passed, 0, sizeof passed);
      |         ^~~~~~
a.cc:4:1: note: 'memset' is defined in header '<cstring>'; this is probably fixable by adding '#include <cstring>'
    3 | #include <map>
  +++ |+#include <cstring>
    4 | #include <string>
a.cc:44:24: error: reference to 'map' is ambiguous
   44 |                 cin >> map[i][j];
      |                        ^~~
/usr/include/c++/14/bits/stl_map.h:102:11: note: candidates are: 'template<class _Key, class _Tp, class _Compare, class _Alloc> class std::map'
  102 |     class map
      |           ^~~
a.cc:13:6: note:                 'bool map [50][50]'
   13 | bool map[50][50];
      |      ^~~