Question

I have a 2D grid for a robot to navigate around. I need to locate the shortest path between two points, the startNode and goalNode. The grid is represented by a n x n multidimensional array.

Robots possible actions (transition)

• Up [0,1]
• down [0,-1]
• left [-1,0]
• right [1,0]

where [x,y]

How would I construct a method to return one of the preceding actions if it does not exceed the multidimensional array bounds?

getAction(x,y)
get potential action from transition
if valid action - in array bounds
return action

Thanks,

Answer 1

Check to see if moving in a certain direction would put you out of bounds.

So it would look something like

String move()
   {

   if(y+1<n)//Can Move Up
   return "up";

   if(y-1>=0)//Can Move Down
   return "down";

   if(x+1<n)//Can Move Right
   return "right";

   if(x-1>=0)//Can Move Left
   return "left";

   return "can't move";

  }

Of course this would always try to move up first, then down, then right, then left. So you can change this code to match your needs.