THE DIAMOND PUZZLE.
(
Unicursal and Route Problems)
IN how many different ways may the word DIAMOND be read in the
arrangement shown? You may start wherever you like at a D and go up or
down, backwards or forwards, in and out, in any direction you like, so
long as you always pass from one letter to another that adjoins it. How
many ways are there?
Answer:
There are 252 different ways. The general formula is that, for words of
n letters (not palindromes, as in the case of the next puzzle), when
grouped in this manner, there are always 2^(n+1) - 4 different readings.
This does not allow diagonal readings, such as you would get if you used
instead such a word as DIGGING, where it would be possible to pass from
one G to another G by a diagonal step.