One-dimensional cellular automata: Difference between revisions

=={{header|REXX}}==

This REXX version will show (as a default) 40 generations, or less if the generations of cellular automata repeat.

<lang rexx>/*REXX pgm displays generations of one-dimensional cellular automata. */

arg $ limit .; if $=='' | $==',' then $=001110110101010 /*default*/

if limit=='' then limit=40 /*default*/

do gen=0 to limit

say ' generation' right(gen,length(limit)) ' ' translate($,'#·',10)

@='·' /*next gener.*/

do j=2 to length($); x=substr($,j-1,3) /*get a cell.*/

if x==011 | x==101 | x==110 then @=overlay(1,@,j) /*cell lives.*/

else @=overlay(0,@,j) /*cell dies.*/

end /*j*/

if $==@ then do; say right('repeats',40); leave; end /*it repeats?*/

$=@ /*now use the next gen of cells. */

end /*gen*/

/*stick a fork in it, we're done.*/</lang>

'''output''' when using the default input

<pre style="overflow:scroll">

generation 0 ··###·##·#·#·#·

generation 1 ··#·#####·#·#··

generation 2 ···##···##·#···

generation 3 ···##···###····

generation 4 ···##···#·#····

generation 5 ···##····#·····

generation 6 ···##··········

repeats

</pre>