PROC PrintArray(BYTE ARRAY a BYTE len)
  BYTE i

  FOR i=0 TO len-1
  DO
    PrintB(a(i))
  OD
  Print(" ")
RETURN

BYTE FUNC NextPermutation(BYTE ARRAY a BYTE len)
  BYTE i,j,k,tmp

  i=len-1
  WHILE i>0 AND a(i-1)>a(i)
  DO
    i==-1
  OD

  j=i
  k=len-1
  WHILE j<k
  DO
    tmp=a(j) a(j)=a(k) a(k)=tmp
    j==+1 k==-1
  OD

  IF i=0 THEN
    RETURN (0)
  FI

  j=i
  WHILE a(j)<a(i-1)
  DO
    j==+1
  OD
  tmp=a(i-1) a(i-1)=a(j) a(j)=tmp
RETURN (1)

PROC Main()
  DEFINE len="5"
  BYTE ARRAY a(len)
  BYTE RMARGIN=$53,oldRMARGIN
  BYTE i

  oldRMARGIN=RMARGIN
  RMARGIN=37 ;change right margin on the screen

  FOR i=0 TO len-1
  DO
    a(i)=i
  OD

  DO
    PrintArray(a,len)
  UNTIL NextPermutation(a,len)=0
  OD

  RMARGIN=oldRMARGIN ;restore right margin on the screen
RETURN