v0=:((,`([,X,])@.(={.))`,@.(0=2|#@]))/&.|. NB. My solution
v1=:3 : '(([:*./ ~:/"1)-: ([:I.2=/\{.)-:X I.@:={:)|: _2[\ y' NB. Check on
correctness
v0 data5 NB. Does not work on empty string, it's OK with me
|domain error: v0
| v0 data5
soln (,:~ v0 L:0)&}:data NB. data=:data1;data2;data3;data4;data5
NB. Same solution with α instead of X
+-------------------+------------------+---------------------+----------------------+
|THEαEQUICKBROWFαFOX|THEαEQUICKBROWFOOX|TαTHEαEQUICKBROWFαFOX|TαTHEαEQUICKBROWFOOαOX|
+-------------------+------------------+---------------------+----------------------+
|THEXEQUICKBROWFXFOX|THEXEQUICKBROWFOOX|TXTHEXEQUICKBROWFXFOX|TXTHEXEQUICKBROWFOOXOX|
+-------------------+------------------+---------------------+----------------------+
v1 S:0 v0 L:0 }:data NB. All (but last) solutions are correct
1 1 1 1
R.E. Boss
-----Original Message-----
From: Programming <programming-boun...@forums.jsoftware.com> On Behalf Of Ric
Sherlock
Sent: vrijdag 5 februari 2021 02:35
To: Programming JForum <programm...@jsoftware.com>
Subject: Re: [Jprogramming] Progressive insertion into a string
Yes as Hauke has previously identified, we need some more test cases to fully
test whether the spec is correctly implemented or not.
I'm thinking that the example outputs you've shown in your email aren't
correct, but I agree that your approach and Raul's generate different solutions
for that input and that your one (and Ben's and the current solution on Rosetta
code) generate the "correct" output as I understand it. Here is an updated set
of test cases:
'data1 soln1'=: 'THEEQUICKBROWFFOX';'THEXEQUICKBROWFXFOX'
'data2 soln2'=: 'THEEQUICKBROWFOOX';'THEXEQUICKBROWFOOX'
'data3 soln3'=: 'TTHEEQUICKBROWFFOX';'TXTHEXEQUICKBROWFXFOX'
'data4 soln4'=: 'TTHEEQUICKBROWFOOOX';'TXTHEXEQUICKBROWFOOXOX'
'data5 soln5'=: '';''
showDigraphs=: dquote@(',' joinstring _2 <\ ])
dd_bg=: {{ ((+ idx&<)#y) {. y ({. ,'X', }.)~ idx =. >:+: 1 i.~ (=/"1) _2 ]\y
}}^:_
dd_md=: dtb@:((] ({.~ , 'X' , }.~) 1 (1 + 2 * i.)~ _2 =/\ ]) {.~ >:@#)
::($:@:,&' ')
digra=: * 2 | i.@# + +/\
dd_rm=: #!.'X'~ 1 j. [: digra # {. }. = }:
dd_pj=: ;@:(_2&(,`([,'X',])@.=/each@<\))^:_
Raul's approach looks as though with some more refinement of how to calculate
which sets of repeat letters need to be split, it should be possible. At the
moment it produces the incorrect result for data4.
([: showDigraphs dd_rm)&> data1;data2;data3;data4;data5
"TH,EX,EQ,UI,CK,BR,OW,FX,FO,X"
"TH,EX,EQ,UI,CK,BR,OW,FO,OX"
"TX,TH,EX,EQ,UI,CK,BR,OW,FX,FO,X"
"TX,TH,EX,EQ,UI,CK,BR,OW,FO,OO,X"
""
Iteratively applying Pascal's approaches do result in all digraphs being split,
but some pairs of letters are split unnecessarily.
On Fri, Feb 5, 2021 at 5:04 AM 'Michael Day' via Programming <
programm...@jsoftware.com> wrote:
> Just before I venture into updating to the correct beta d...
>
> Raul's is elegant, single-pass and pretty spare. Here's a verbose,
> inelegant, multi-pass one, but it seems to work, except perhaps for
> the last example, below.
>
> I stuck with _2 which means that with odd length strings an error is
> thrown on the last pair which is actually not a pair, so needs to be catered
> for.
>
> anyway, (it should appear on one line):
> dedouble =: dtb@:((] ({.~ , 'X' , }.~) 1 (1 + 2 * i.)~ _2 =/\ ])
> {.~
> >:@#) ::($:@:,&' ')
>
> dtb is delete trailing blanks, in strings, I think.
>
> dedouble^:_'THEEQUICKBROWFFOOX'
> THEXEQUICKBROWFXFOOX
> dedouble^:_'THEEQUICKBROWFOOX'
> THEXEQUICKBROWFOOX
>
> This next example is a bit unlikely to occur, but is this what's required?
> dedouble 'THEEQUICKBROWFOOOX'
> THEXEQUICKBROWFOOOX
>
> Raul's version doesn't agree with mine here! Is this result prederred?
> rmdedouble 'THEEQUICKBROWFOOOX'
> THEXEQUICKBROWFOOOX
>
> Cheers,
>
> Mike
>
>
> On 04/02/2021 14:46, Raul Miller wrote:
> > Ah, I see it now -- I should have looked closer at your digraphs.
> >
> > Here's a fixed version:
> >
> > digra=: * 2 | i.@# + +/\
> > dedouble=: #!.'X'~ 1 j. [: digra #{.}.=}:
> >
> > (I could not think of a good name for the "compress out splits of
> > non-digraphs" mechanism.)
> >
> > The moral of the story here is that numeric calculations can often
> > replace simple recursive processes. (Because numbers can be defined
> > recursively.)
> >
> > I hope this helps,
> >
>
>
> --
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