// Arithmetic Derivative
//  https://rosettacode.org/wiki/Arithmetic_derivative#

local fn DoIt( N as short) as short
  short L,F,Z
  L = 0: F = 3: Z = ABS(N)
  IF Z<2 THEN exit fn

  1 IF Z MOD 2 = 0 THEN L=L+N\2: Z=Z\2: GOTO 1
  2  IF F>Z THEN exit fn
  3 IF Z MOD F = 0 THEN L=L+N\F: Z=Z\F: GOTO 2

  F=F+2
  goto 1

end fn = L

_Window = 1

window _Window,@"Arithmetic Derivative",fn cgrectmake(0,0,640,400)
windowcenter(_Window)

short N,L,LineCount
FOR N = -99 TO 100
L = fn DoIt(N): PRINT USING "########";L;
LineCount ++
if LineCount = 10 then print : LineCount = 0
NEXT

handleevents