Multiple paths can be drawn on the grid below following along ten of the twelve segments but never using any segment twice.
+--+--+
| | |
+--+--+
| | |
+--+--+
How many such paths are there?
I found 9 ignoring reflections and rotations:
+-a-+-b-+
|c |d |f
+-f-+-g-+
|h |i |j
+-k-+-l-+
There have to be two unused segments.
The path is only possible if the missing segments are a&c, d&f, or f&g.
Missing f&g: One path:
achkidbfjl
Missing d&f: Three paths:
jlkhcabegi
jligebachk
giljebachk
Missing a&c: Five paths:
gfhkidbejl
ebdfhkigjl
ebdikhfgjl
gfhkljebdi
ifhkljebdg
I wouldn't be surprised if I missed one or two.
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Posted by Jer
on 2016-02-19 11:03:32 |