CGD (Common Greatest Divisor) script multiple nr's

[Montfrooij]

After a search on this forum AND the help files I did not find any satisfying functions to calculate the CGD (Common Greatest Divisor) for more than 2 numbers.

Here is an example of my script.

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;Example data, enter your nr's in this array
dim $nr[4] ;In this example just 4 nr's are entered, so therefor the [4]
$nr[0] = 44
$nr[1] = 33
$nr[2] = 22
$nr[3] = 11
_cgdMultiple($nr) ;Call the multiple function

Func _cgdMultiple($aNr) ;Function to call _cgd multiple times and return the cgd of all nr's in the $aNr array supplied
For $i = 1 to ubound($aNr) - 1  ;loop through all nr's, the -1 is because we start with [0] but dim until [3]
  ;First time
  if $i = 1 Then
   $cgd = _cgd($aNr[$i-1],$aNr[$i])
   MsgBox(0,$i,$aNr[$i-1] & "-" & $aNr[$i] & "-" & $cgd) ;Just to show what is happening
  Else ;Next time
   $cgdprev = $cgd ;Just to see what is happening, can be removed, but than the next line needs to be _cgd($cgd,$aNr[$i])
   $cgd = _cgd($cgdprev,$aNr[$i])
   MsgBox(0,$i,$cgdprev & "-" & $aNr[$i] & "-" & $cgd) ;Just to show what is happening
  EndIf
Next
MsgBox(0,"Result","cgd = " & $cgd)
EndFunc ;===> _cgdMultiple

Func _cgd($n, $m) ;Function to return the cgd of two nr's
if $n > 0 and $m > 0 and StringIsInt($n) and StringIsInt($m) Then ;Check for valid input
  if ($n < $m) Then ;Make sure $n is bigger than $m
   $z = $n
   $n = $m
   $m = $z
  EndIf
  $r = 1
  while $r <> 0 ;Subtract the floor of $n/m from $n to get the cgd
   $q = Floor($n/$m)
   $r = $n - ($m*$q)
   $n = $m
   $m = $r
  WEnd
Else
  $n = 0 ;Not possible
EndIf
return $n
EndFunc ;===> _cgd

That's all.

Comments / additions / corrections are welcome.

BR,

Peter

Edited March 21, 2012 by Montfrooij

[Montfrooij]

Thanks, edited the mixup.

English is still hard to write....

Your function is a bit shorter, I will still need to verify that $a > $b so only the while is affected.

I actually ended up not using the script, so when there is time left I will implement your version.