Kolakoski sequence: Difference between revisions

=={{header|Arturo}}==

<lang rebol>kolakoski: function [a, length][

result: array.of: length 0

i: new 0

k: new 0

loop.forever a 'x [

result\[i]: x

if result\[k] > 1 [

loop 1..dec result\[k] 'j [

inc 'i

if i = length -> return result

result\[i]: result\[i-1]

]

]

inc 'i

if i = length -> return result

inc 'k

]

return result

]

possibleKolakoski?: function [seq][

prev: seq\0

count: new 1

rle: new []

loop 1..dec size seq 'i [

if? seq\[i] = prev -> inc 'count

else [

'rle ++ count

count: new 1

prev: seq\[i]

]

]

loop.with:'i rle 'val [

if val <> seq\[i] -> return false

]

return true

]

Seqs: [[1 2] [2 1] [1 3 1 2] [1 3 2 1]]

Lens: [20 20 30 30]

loop combine Seqs Lens 'c [

generated: kolakoski c\0 c\1

print ["First" c\1 "members of the sequence generated by" c\0 ":"]

print generated

print ["Possible Kolakoski sequence?" possibleKolakoski? generated]

print ""

]</lang>

{{out}}

<pre>First 20 members of the sequence generated by [1 2] :

1 2 2 1 1 2 1 2 2 1 2 2 1 1 2 1 1 2 2 1

Possible Kolakoski sequence? true

First 20 members of the sequence generated by [2 1] :

2 2 1 1 2 1 2 2 1 2 2 1 1 2 1 1 2 2 1 2

Possible Kolakoski sequence? true

First 30 members of the sequence generated by [1 3 1 2] :

1 3 3 3 1 1 1 2 2 2 1 3 1 2 2 1 1 3 3 1 2 2 2 1 3 3 1 1 2 1

Possible Kolakoski sequence? true

First 30 members of the sequence generated by [1 3 2 1] :

1 3 3 3 2 2 2 1 1 1 1 1 3 3 2 2 1 1 3 2 1 1 1 1 3 3 3 2 2 1

Possible Kolakoski sequence? false</pre>