INCLUDE "D2:SORT.ACT" ;from the Action! Tool Kit

BYTE FUNC Contains(BYTE ARRAY a BYTE len,b)
  BYTE i

  IF len=0 THEN
    RETURN (0)
  FI
  FOR i=0 TO len-1
  DO
    IF a(i)=b THEN
      RETURN (1)
    FI
  OD
RETURN (0)

BYTE FUNC Gcd(BYTE a,b)
  BYTE tmp

  IF a<b THEN
    tmp=a a=b b=tmp
  FI

  WHILE b#0
  DO
    tmp=a MOD b
    a=b b=tmp
  OD
RETURN (a)

BYTE FUNC AreSame(BYTE ARRAY a,b BYTE len)
  BYTE i

  IF len=0 THEN
    RETURN (1)
  FI

  SortB(a,len,0)
  SortB(b,len,0)
  FOR i=0 TO len-1
  DO
    IF a(i)#b(i) THEN
      RETURN (0)
    FI
  OD
RETURN (1)

PROC CalcEkg(BYTE start,limit BYTE ARRAY ekg)
  BYTE len,i

  ekg(0)=1 ekg(1)=start
  FOR len=2 TO limit-1
  DO
    i=2
    DO
      IF Contains(ekg,len,i)=0 AND Gcd(ekg(len-1),i)>1 THEN
        ekg(len)=i
        EXIT
      FI
      i==+1
    OD
  OD
RETURN

BYTE FUNC CalcConvergence(BYTE ARRAY a,b BYTE len)
  BYTE i

  FOR i=2 TO len-1
  DO
    IF a(i)=b(i) AND AreSame(a,b,i)=1 THEN
      RETURN (i+1)
    FI
  OD
RETURN (0)

PROC PrintSeq(BYTE start BYTE ARRAY ekg BYTE len)
  BYTE i

  PrintF("EKG(%B)=",start)
  FOR i=0 TO len-1
  DO
    IF i>0 THEN Put(32) FI
    PrintB(ekg(i))
  OD
  PrintE("...")
RETURN

PROC Main()
  DEFINE PTR="CARD"
  DEFINE LIMIT="100"
  DEFINE SEQCOUNT="5"
  DEFINE PART="10"
  DEFINE EKG1="1"
  DEFINE EKG2="2"
  BYTE ARRAY buf(500),starts=[2 5 7 9 10]
  PTR ARRAY ekg(SEQCOUNT)
  BYTE i,conv

  Put(125) PutE() ;clear the screen

  FOR i=0 TO SEQCOUNT-1
  DO
    ekg(i)=buf+LIMIT*i
    CalcEkg(starts(i),LIMIT,ekg(i))
    PrintSeq(starts(i),ekg(i),PART)
  OD

  conv=CalcConvergence(ekg(EKG1),ekg(EKG2),LIMIT)
  PrintF("%EEKG(%B) and EKG(%B) ",starts(EKG1),starts(EKG2))
  IF conv=0 THEN
    PrintF("do not converge within %B items",LIMIT)
  ELSE
    PrintF("converge at index %B",conv)
  FI
RETURN