Comments on: Slip sliding away: insane brain games

Slip sliding away: insane brain games

taz — Tue, 22 Jun 2004 04:45:00 -0800

This should get your goat: Insanely hard sliding block puzzles. (Can't take the heat? Maybe you'd like to try an insanely hard sliding door maze instead?)

By: psychotic_venom

psychotic_venom — Tue, 22 Jun 2004 06:47:43 -0800

Holy crap that's hard.

By: Prospero

Prospero — Tue, 22 Jun 2004 07:27:34 -0800

Excellent post.

By: evening

evening — Tue, 22 Jun 2004 09:27:09 -0800

ok, how do you solve these types of puzzles? I suck at "easy" ones. anyone have a guide or something that explains strategy for these??

By: DrJohnEvans

DrJohnEvans — Tue, 22 Jun 2004 10:22:45 -0800

Nnnnnnngh.

By: DevilsAdvocate

DevilsAdvocate — Tue, 22 Jun 2004 11:14:50 -0800

It's possible to trap yourself in that sliding door maze. I finally solved it, though.

By: dness2

dness2 — Tue, 22 Jun 2004 12:39:43 -0800

Damn you taz, and your little dog too.

By: szg8

szg8 — Tue, 22 Jun 2004 13:22:11 -0800

Ok, that sliding door puzzle is insanely impossible.

By: DevilsAdvocate

DevilsAdvocate — Tue, 22 Jun 2004 15:30:43 -0800

evening: judging from this paper [PDF], help doesn't seem very likely:

What can be said about the difficulty of solving this kind of puzzle, in general? Martin Gardner devoted his February, 1964 Mathematical Games column to sliding-block puzzles. This is what he had to say:
These puzzles are very much in want of a theory. Short of trial and error, no one knows how to determine if a given state is obtainable from another given state, and if it is obtainable, no one knows how to find the minimum chain of moves for achieving the desired state.
Forty years later, we still do not have such a theory. It turns out there is a good reason for this: sliding-block puzzles have recently been shown to belong to a class of problems known as PSPACE-complete. These problems are thought to be even harder than their better-known counterparts, the NP-complete problems (such as the traveling salesman problem).