It should work on arrays of the form
a + b * i, where a and b are integer scalars, and i is an integer vector.
So, if
q=: 6 + 7*1 2 5 11 23,
applying this function yields
(-/ .* % -/ .+)@:(2 2&$) q
7.4
I think you need instead something like
Difference’s greatest common divisor,
dgcd =: +./@:(2 -~/\ ])
So
dgcd q
7
It’s a bit more complicated to recover the factors, 1 2 5 ..., which seem to be
required in the Quora problem:
(](([-|~)%])dgcd) q
1 2 5 11 23
This works for the original array, too,
(](([-|~)%])dgcd) 21 38 55 106
1 2 3 6
And
dgcd 21 38 55 106
17
Sorry for any formatting problems - typing on iPad,
Mike
Please reply to mike_liz....@tiscali.co.uk.
Sent from my iPad
> On 14 Aug 2018, at 23:18, Jose Mario Quintana <jose.mario.quint...@gmail.com>
> wrote:
>
> (-/ .* % -/ .+)@:(2 2&$)21 38 55 106
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