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Talk:Permutations with repetitions: Difference between revisions

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Talk:Permutations with repetitions (view source)

Revision as of 14:16, 21 May 2013

29 bytes added ,  11 years ago
Is the Mathematica solution correct?
(→‎REXX implementation limits: added another variant of REXX version 2. -- ~~~~)
(Is the Mathematica solution correct?)
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==Mathematica solution incorrect?==
The task description says combination must be produced one at a time.
The Mathematica solution uses Tuples, which return a list of all permutations at once.
Is this a correct solution?
--[[User:Soegaard|Soegaard]] ([[User talk:Soegaard|talk]]) 14:16, 21 May 2013 (UTC)
 
==REXX implementation limits==
 
Line 6 ⟶ 12:
 
For Regina REXX 3.3,   3.4,   3.5, REXX gives a SYNTAX error:
:::::: Error 12 running "C:\xxxxxx.REX", line 29: [Clause > 1024 characters]
 
For Regina REXX 3.6,   3.7, REXX "crashes" somewhere less than a statement length of 1932,
Line 19 ⟶ 25:
For what's it worth, I believe REXX should raise the SYNTAX condition.
 
[The reason I mention the older versions of Regina REXX is that Regina REXX<br>virtual 3.3memory usesfor lessthose REXX programs which use a ''lot'' of stemmed variables (possibly a
<br>virtual memory for those REXX programs which use a ''lot'' of stemmed variables (possibly a
<br>memory leak), so the use of the older Regina release is forced in lieu of a fix.
 
For PC/REXX and Personal REXX, it depends on what the RXISA ('''SET''' environmental variable).
<br>These two REXXes either give:
:::::: Error 11 on line 29 of c:\xxxxxx.REX" Control stack full
<br>
:::::: Memory full: symbol
:::::: Error 5 on line 29 of C:\xxxxxx.REX: Machine resources exhausted
 
somewhere between 568 and 597 bytes.
 
It should be noted that most people use the maximum for the RXISA &nbsp; (which is 40K).
 
As far as I can tell, R4 and ROO have noRno (real) limitation for the length of an INTERPRET instruction,
<br>and that is probably true of CMS REXX and TSO REXX &nbsp; (it's been too long since I used those
<br>two flavors of REXX).
 
::::::::::: -- [[User:Gerard Schildberger|Gerard Schildberger]] ([[User talk:Gerard Schildberger|talk]]) 20:52, 12 May 2013 (UTC)
 
----
 
==another variant of the 2nd REXX version==
This REXX version:
* simplifies many statements
Line 53 ⟶ 58:
* eliminates an extra &nbsp; ''';''' &nbsp; (semicolon) from the INTERPRET clause
* eliminates the need for counting the permutations
<br>If any of these improvements could/would be of use, that's fine. &nbsp; I plan to delete this entry in a couple of weeks. -- [[User:Gerard Schildberger|Gerard Schildberger]] ([[User talk:Gerard Schildberger|talk]]) 04:32, 13 May 2013 (UTC)
<lang rexx>/*REXX*/ parse arg n m s names
if n='' then n=3='' then m=(s,'N') then s=left('',s)
if m='' then m=2
if datatype(s,'N') then s=left('',s)
 
do k=1names='' to n then e.k=k
if names='' then e.k=k
else parse var names e.k names
end /*k*/
a=''
do i=1 to m; a=a'do d'i"=1 to n;"; end /*i*/
a=a'z=e.d1'
do j=2 to m; a=a"||s||e.d"j; end /*j*/
 
a=a';say z'copies(";end",m)
if m==0 then do; say '1 permutation, a "null".'; exit; end
interpret a
say n**m 'permutations'</lang>
Anonymous user
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