A couple of weeks ago I
managed to acquire a couple of rather interesting little restricted
tray packing puzzles from Wil… and I managed to find some puzzling time
earlier this week so I hauled them out and worked
my way through them in between one of my other little projects.
Pocket had been
entered in the 2018 Nob Yoshigahara Puzzle Design Competition but I
hadn’t been able to have a bash at it in San Diego – so when I saw a
copy in one of Wil’s crates I pounced on it. Designed by Koichi Miura and MINE, my
copy came with two sets of pieces, each of which needs to be inserted
into the tray through the slot at the top… which holds the only little
wrinkle: a single obstructing voxel.
The two sets of pieces
appear to be a beginner’s puzzle and a slightly more advanced puzzle –
with the beginner’s pieces all being made up of two pairs of blocky
pieces (C’s and P’s – both hexominoes) and a little
playing will convince you that there’s probably only really one way to
arrange all of those pieces in the tray, so the puzzle reduces to
finding a way to get them in there… as I said, I think this is the
beginner’s challenge – in fact, it wasn’t even used
in the Design Competition.
The second set of
pieces provides a slightly trickier challenge: all four pieces are
different and they all have 45 degree corners / cut-outs… which makes
for a lot of interesting ways to combine them in the
shape and size of the tray provided… sadly, however, most of those
arrangements are precluded by that one, pesky little voxel sitting in
the centre of the top slot… I should know, as I spent an awfully long
time trying various arrangements that turned out
to be un-assembleable. (It IS a word, now!). Finding the one that does
work is quite a treat – it definitely rewards the solver in a delightful
manner.
I hadn’t ever seen or heard about
Packing Puzzle 4P until I stumbled across it at Peter’s place – I
did recognise the designer’s name - Hajime Katsumoto – and I have
rather enjoyed a few of his other designs, so I took a punt and I ended
up being rather glad I did.
There’s a two-sided
tray, helpfully titled “Puzzle 1” and “Puzzle 2” and a set of four
P-pentominoes… it’s pretty clear from the get-go that you need to put
the four pieces into each of the (slightly obstructed)
4 * 5 frames. The holes on the first side are big enough to allow
pieces to be inserted either way up, which is helpful… and you can
fiddle around for a while and realise that you’re going to need to be a
little creative in order to find a solution to this
one… it’s quite a cute little solution and gives a nice little “A-Ha!”
moment.
Puzzle 2 on the other
hand is a bit of a sod – it kept me going for a lot longer! The holes on
the second side are 5 voxels and P-shaped – so you can simply drop in
the last two pieces, right?! Fine… all you
need to do is position the first two pieces correctly and you’re done…
except you can’t! I spent ages trying variations on a theme, doing
things this way and then that, and every single time I ended up with the
same conclusion – it doesn’t work! Unless I
can get one piece to magically pass THROUGH the other, they ain’t
getting into the position I want them to be in…
Desperation led me to
resort to Think(C)ing (it’s been a while!) and then even to consider
CHEATing – although I did manage to stop myself just short of doing that
when I realised I wouldn’t actually be able
to UNDO the thing I was about to DO… until the right little briefest
flash of inspiration struck and seconds later side 2 was solved – love
it!
The last puzzle in this
post turned out to be my first and second prize for A2P2 – each year my
competition winners are invariably puzzle collectors who already “have
everything” – so finding a puzzle they haven’t
got turns into an annual conundrum for me… with Wil Strijbos invariably
managing to turn up something SO NEW that nobody could possibly have a
copy yet –
Framed Jigsaw was that puzzle this year.
The original design
comes courtesy of Hajime Katsumoto (yes there’s a spelling mistake on
the puzzle... sorry) but it’s been “Streetwise’d” and “JCC’d” resulting
in the improved version here – the pic shows the
starting position with what appears to be a nicely checkered set of
jigsaw pieces under a partial clear frame – with a central 2*2 hole…
almost fully constructed – except for the final piece that obviously(!?)
belongs in the top right hand corner – is the wrong
colour for a neat checkerboard pattern, and has a tongue and a groove too many… which is odd.
Removing the pieces
tells you a lot about how interesting this puzzle is going to be… a
piece come out easily, but then you need to start moving things around
to get the rest of the pieces out: the central opening
is big enough for the 2*2 pieces, but not big enough for any tongues
projecting outwards… so you need to manoeuvre pieces to be fully in the
open frame in order to remove them – taking things out at an angle
relative to the tray, isn’t possible at all…
Get all the pieces out
and some things become apparent, like all tongues fit all grooves – and
there are the same (ergo just enough) number of each…which is great: it
means there are LOTS of ways of constructing
a 4*4 square with those pieces.
How many of those do you think are assembleable (yup, still a word! Work with me here…)?
Very, very few!
You need to be able to
keep as many degrees of freedom available as you progress or you’ll find
yourself up a blind alley that simply won’t allow the last couple of
pieces to be inserted… and let me tell you
that I found a LOT of ways of almost doing this one…there is a solution
to be found, and I found it quite tough – Nick on the other hand seemed
to solve it rather rapidly, and I’m not sure how Ali’s doing/done… at
least I know it wasn’t trivial! :-)