On Wed, Dec 12, 2018 at 1:25 PM 'Mike Day' via Programming <[email protected]> wrote: > It occurred to me yesterday, though I haven’t coded it, that you can work > through twice, first for the minimum suitable spanning box, and second for > that box extended one row up and down and one column left and right. The > inner regions are those whose size doesn’t change. Probably pretty > inefficient, but easier to understand?
What I did was ensure my grid had at least one row of empty grid cells on the border. I am not sure that that's sufficient. Intuitively, I would think the grid should be twice times the size necessary to contain the named coordinates for the worst cases (with the named coordinates in the central part), but it worked for every example I've encountered, so far. (On the other hand, if that single extra grid coordinate is sufficient, for the worst case, it might be that I don't even need that single extra row.) "Fortunately", ... Advent of Code doesn't require you solve for the general case. FYI, -- Raul ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
