Slip sliding away: insane brain games

June 22, 2004 4:45 AM

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?)
posted by taz (8 comments total)

Holy crap that's hard.
posted by psychotic_venom at 6:47 AM on June 22, 2004

Excellent post.
posted by Prospero at 7:27 AM on June 22, 2004

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??
posted by evening at 9:27 AM on June 22, 2004

Nnnnnnngh.
posted by DrJohnEvans at 10:22 AM on June 22, 2004

It's possible to trap yourself in that sliding door maze. I finally solved it, though.
posted by DevilsAdvocate at 11:14 AM on June 22, 2004

Damn you taz, and your little dog too.
posted by dness2 at 12:39 PM on June 22, 2004

Ok, that sliding door puzzle is insanely impossible.
posted by szg8 at 1:22 PM on June 22, 2004

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).

posted by DevilsAdvocate at 3:30 PM on June 22, 2004