PROC ToBinaryStr(BYTE n CHAR ARRAY s)
  BYTE i

  s(0)=8 i=8
  SetBlock(s+1,8,'0)
  WHILE n
  DO
    s(i)=(n&1)+'0
    n==RSH 1
    i==-1
  OD
RETURN

PROC PrintB2(BYTE n)
  IF n<10 THEN Put(32) FI
  PrintB(n)
RETURN

PROC PrintBin5(BYTE n)
  CHAR ARRAY s(9),sub(6)

  ToBinaryStr(n,s)
  SCopyS(sub,s,4,s(0))
  Print(sub)
RETURN

BYTE FUNC Encode(BYTE n)
RETURN (n XOR (n RSH 1))

BYTE FUNC Decode(BYTE n)
  BYTE res

  res=n
  DO
    n==RSH 1
    IF n THEN
      res==XOR n
    ELSE
      EXIT
    FI
  OD
RETURN (res)

PROC Main()
  BYTE i,g,b
  CHAR ARRAY sep=" -> "

  FOR i=0 TO 31
  DO
    PrintB2(i) Print(sep)
    PrintBin5(i) Print(sep)
    g=Encode(i)
    PrintBin5(g) Print(sep)
    b=Decode(g)
    PrintBin5(b) Print(sep)
    PrintB2(b) PutE()
  OD
RETURN