INT FUNC BinarySearch(INT ARRAY a INT len,value)
  INT low,high,mid

  low=0 high=len-1
  WHILE low<=high
  DO
    mid=low+(high-low) RSH 1
    IF a(mid)>value THEN
      high=mid-1
    ELSEIF a(mid)<value THEN
      low=mid+1
    ELSE
      RETURN (mid)
    FI
  OD
RETURN (-1)

PROC Test(INT ARRAY a INT len,value)
  INT i

  Put('[)
  FOR i=0 TO len-1
  DO
    PrintI(a(i))
    IF i<len-1 THEN Put(32) FI
  OD
  i=BinarySearch(a,len,value)
  Print("] ") PrintI(value)
  IF i<0 THEN
    PrintE(" not found")
  ELSE
    Print(" found at index ")
    PrintIE(i)
  FI
RETURN

PROC Main()
  INT ARRAY a=[65530 0 1 2 5 6 8 9]

  Test(a,8,6)
  Test(a,8,-6)
  Test(a,8,9)
  Test(a,8,-10)
  Test(a,8,10)
  Test(a,8,7)
RETURN