Hi,
The version I know from
https://github.com/kevinlawler/kona/wiki/Idioms
is
mss=: [: >./ (0 >. +)/\.
It fails on lists of length 0 or 1 but is very concise; the following works on
all list lengths but has a few extra characters:
mss1=: [: >./ [: (0 >. +)/\. ,&0
which is an almost literal t
Trying your patience -
better to use \. instead of ONE of the \ as in
mxsasumcrude =: >./@:(>./@:( +/\. ) \ ) NB. less space
or
mxsasumcrude =: >./@:(>./@:( +/\ ) \. ) NB. more space
The version using only " \ " goes wrong with lots of negative values.
Better stop now!
Mike
On 24/02/2019
Sorry - correcting mxsasumcrude (below) - some brackets went missing.
It should be
mxsasumcrude =: >./@:(>./@:(+/\)\)
Time and space much the same as below.
Mike
Here's what I previously posted, with inline correction...
=
Thanks to Raul f
Thanks to Raul for pointing out the Rosetta Stone entries at
https://rosettacode.org/wiki/Greatest_subsequential_sum#J
I tried
ts ' maxss q16' [q16 =: 2#8000$ '
but gave up waiting, seeing Windows' Task Manager's display of total
memory
climbing towards 15GB.
Then I spotted maxSS and m
Might be worth adding to
https://rosettacode.org/wiki/Greatest_subsequential_sum#J ?
Thanks,
—
Raul
On Sunday, February 24, 2019, 'Jon Hough' via Programming <
[email protected]> wrote:
> Reference: https://en.wikipedia.org/wiki/Maximum_subarray_problem
>
> This is the problem:
> Given
OK, Jon - I looked at wiki and implemented Kadane, with mxsasum
(explicit) and mxsasumt (tacit)
returning just the best sum, while mxsa returns the subarray.
NB. Kadane's algorithm as presented in wiki
NB. def max_subarray(A):
NB. max_ending_here = max_so_far = A[0]
NB. for x in A[1:
Reference: https://en.wikipedia.org/wiki/Maximum_subarray_problem
This is the problem:
Given an array of numbers, find the contiguous subset of maximum sum. i.e. find
the maximum sum subarray.
Example:
R=: 3 4 _5 2 1 1
The maximum subarray is 3 4
Kadane's algorithm is a linear time algorithm to
