Gunmen problem
There is a map of 8x8. 0 is an empty space and 1 is a wall.
{0,1,0,1,0,1,0,1 },
{0,0,0,0,0,1,0,0 },
{1,0,1,0,0,1,0,1 },
{0,0,0,0,0,0,0,0 },
{0,0,0,1,0,0,0,0 },
{0,0,0,0,0,1,0,1 },
{0,1,0,0,0,0,0,0 },
{0,0,0,0,1,0,1,0 }
A gunman can shoot vertically and horizontally. They cannot see over the wall and diagonal. We want to place as much as gunmen in this room.
One example of solutions is:
2 1 2 1 2 1 2 1
0 0 0 2 0 1 0 2
1 2 1 0 0 1 0 1
0 0 0 0 0 0 0 2
0 0 2 1 0 2 0 0
0 0 0 2 0 1 0 1
2 1 0 0 0 0 0 2
0 2 0 0 1 2 1 0