DEFINE MAXDECK="5000"

PROC Order(INT ARRAY deck INT count)
  INT i

  FOR i=0 TO count-1
  DO
    deck(i)=i
  OD
RETURN

BYTE FUNC IsOrdered(INT ARRAY deck INT count)
  INT i

  FOR i=0 TO count-1
  DO
    IF deck(i)#i THEN
      RETURN (0)
    FI
  OD
RETURN (1)

PROC Shuffle(INT ARRAY src,dst INT count)
  INT i,i1,i2

  i=0 i1=0 i2=count RSH 1
  WHILE i<count
  DO
    dst(i)=src(i1) i==+1 i1==+1
    dst(i)=src(i2) i==+1 i2==+1
  OD
RETURN

PROC Test(INT ARRAY deck,deck2 INT count)
  INT ARRAY tmp
  INT n

  Order(deck,count)
  n=0
  DO
    Shuffle(deck,deck2,count)
    tmp=deck deck=deck2 deck2=tmp
    n==+1
    Poke(77,0) ;turn off the attract mode
    PrintF("%I cards -> %I iterations%E",count,n)
    Put(28) ;move cursor up
  UNTIL IsOrdered(deck,count)
  OD
  PutE()
RETURN

PROC Main()
  INT ARRAY deck(MAXDECK),deck2(MAXDECK)
  INT ARRAY counts=[8 24 52 100 1020 1024 MAXDECK]
  INT i

  FOR i=0 TO 6
  DO
    Test(deck,deck2,counts(i))
  OD
RETURN