On page 89 of an old puzzle book in my bathroom (one of several
possible answers on page 111 of the same book)
http://www.amazon.com/exec/obidos/ASIN/071372000X
I came across a puzzle. The type of puzzle is called "Doublet" and was
invented by the wonderful Charles Dodgson (Lewis Carroll). You start
with one word. You change one letter in that word to create another
word. You change one letter in the resulting word to arrive at a third
word. The goal is to keep changing one letter at a time and have a
word at every stage as you move from a starting word to a goal word,
using either a pre-determined number of intermediate words or as few
intermediate words as possible.
Their puzzle was
M E N S A
_ _ _ _ _
_ _ _ _ _
_ _ _ _ _
_ _ _ _ _
_ _ _ _ _
_ _ _ _ _
W O R L D
So, you have six intermediate words to fill in. They provide a
solution, and note that they don't think it can be done in fewer words.
Note that every position in the terminal word has a different letter
than is found in that position in the initial word. Since exactly one
letter can change in each step, doing it in one fewer steps would mean
that the first step would have to be one of (case used to help note
the pattern)
wENSA MoNSA MErSA MENlA MENSd
*and* the penultimate step would have to be one of
mORLD WeRLD WOnLD WORsD WORLa
So, I can see why they might arrive at their conclusion that doing it
one fewer steps is not possible.
I thought folks might find fun with perl in seeing how elegant a
program they can write to find the "best" solution for
S N A K E
: : : : :
: : : : :
: : : : :
C A M E L
Maybe you want a program that finds the shortest solution the fastest.
Maybe you want a program that finds the shortest solution with the
most common words (none of those words we've never heard of before).
Another challenge might be to write a program that finds particularly
hard pairs of words... either they require oodles of steps, or they
can be done in fewer steps, but only by using really obscure words.
To aid in your fun, please find a Big-Ass list of five letter words
(and non-words) with word-commonality, and definition information in
many cases and assorted other meta-data. The list contains over
120,000 five letter entries.
http://wickline.org/fivers.tar.gz
Also, if anyone has any other fun things to do with five letter words,
this might be a usefull resource.
-matt
