Hi Mike,
Regarding point 1:, that was me, Jon Hough.
--------------------------------------------
On Mon, 4/9/18, 'Mike Day' via Programming <programm...@jsoftware.com> wrote:
Subject: Re: [Jprogramming] Quora Problem
To: programm...@jsoftware.com
Date: Monday, April 9, 2018, 5:33 PM
Hello Skip
Points:
0: is this the same
Quora which keeps sending me e-messages with headers
such as
"What are the best
things for Oxford students to do on weekends?"
"What is the best and most prestigious
English university nowadays?
Oxford?
Cambridge?"
- both received
yesterday/today!
1: A reply
has just popped up from a sender which I can only see as
"Programming Forum",
probably not from Jon Hough, but replying to
his comment. It deals in
the
combinatorial
approach which has to be used
for larger such problems. It would be nice
to know who.
2: Here's a smaller brute force approach.
Consider valid numbers as
sextuplets of
digits
drawn from 0 1 2, possibly followed
by adding 1 to each digit. We
don't
need to worry at
all about 3 to 9 to start
with.
So, (working on
digits 0 1 2):
100 200 300 400 { sext
=: 3#.inv i.3^6 NB. show a few members of
the set
0 1 0 2 0 1
0 2 1 1 0 2
1 0 2 0 1 0
1 1 2 2 1 1
+/(3>>./@:((1, 2~:/\])#;.1 ]))"1
sext
On 09/04/2018 06:51, Skip Cave wrote:
> Here's a fun math challenge on
Quora:
>
> Find the
number of 6-digit numbers made up of the digits 1, 2, and 3
which
> have no digit recurring three or
more times, consecutively?
>
> The link to my answer on Quora is: https://goo.gl/BzBDQe
>
> Skip Cave
> Cave Consulting LLC
>
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