cool,
http://code.jsoftware.com/wiki/Essays/Progressive_Index-Of
oc=: i.~ (] - {) /:@/:
pi=: #@[ ({. i.&(,.oc) }.) [ i. ,
'a' (] {~ i.@#@] -. pi~) 'cbaab'
cbab
my original version, (fails some of the order requests)
delfromend =: ;@:(] (</.~@[ }.&.>~ {./.) +/@:(=/))
'a' delfromend&, 'cbaab'
cbba
----- Original Message -----
From: Henry Rich <[email protected]>
To: [email protected]
Sent: Monday, July 25, 2016 11:02 AM
Subject: Re: [Jprogramming] challenge: dyad -. but removing the number of
copies of x in y
See Progressive Index in the Wiki
Henry Rich
On 7/25/2016 10:41 AM, 'Pascal Jasmin' via Programming wrote:
> write function delfromend (naming things is hard) such that
>
> 'cabd' delfromend 'cbaab'
> ba
>
> 18 (delfromend~ ; delfromend)&q: 54
> ┌┬─┐
> ││3│
> └┴─┘
>
> 'aaaa' delfromend 'cbaab'
> cbb
>
>
>
> removes as many instances of x that exist in y. Taking out items from the
> end of y. Though a bit easier is to just group items by "key" for output.
>
>
> (,<'a') delfromend ;/ 'cbaab'
> ┌─┬─┬─┬─┐
> │c│b│b│a│
> └─┴─┴─┴─┘
> ----------------------------------------------------------------------
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