/* NetRexx */
options replace format comments java crossref savelog symbols

/*REXX program to sort an interesting integer list.*/

bell = '1 1 2 5 15 52 203 877 4140 21147 115975'      /*some Bell numbers.*/
bern = '1 -1 1 0 -1 0 1 0 -1 0 5 0 -691 0 7 0 -3617'  /*some Bernoulli num*/
perrin = '3 0 2 3 2 5 5 7 10 12 17 22 29 39 51 68 90' /*some Perrin nums. */
list = bell bern perrin                               /*combine the three.*/

size = list.words

a = 0
loop j = 1 for size
  a[j] = list.word(j)
  end j

say '  as is='list
a[0] = size
esort(a, size)
bList = ''

loop j = 1 for size
  bList = bList a[j]
  end j

blist = bList.strip
say ' sorted='bList

return

/*----------------------------------ESORT subroutine--------------------*/
method esort(a, size) public static
--esort: procedure expose a.;

  h = a[0]

  loop while h > 1
    h = h % 2
    loop i = 1 for a[0] - h
      j = i
      k = h + i
      loop while a[k] < a[j]
        t    = a[j]
        a[j] = a[k]
        a[k] = t
        if h >= j then leave
        j = j - h
        k = k - h
        end
      end i
    end

return