Inverted 5 Posted October 22, 2012 (edited) Just wanted to waste some time and converted some php code to AutoIt : $primeNumbers = array(); $output = ''; $start = microtime(TRUE); for ($i = 2; $i < 100000; $i++) { $divisible = false; foreach ($primeNumbers as $number) { if ($i % $number == 0) { $divisible = true; break; } } if ($divisible == false) { $primeNumbers[] = $i; $output .= $i; } } echo count($primeNumbers), "n"; echo "time: ", microtime(TRUE) - $start, "n"; #include <Array.au3> Dim $primes[1] Local $number $output = '' For $i = 2 To 100000 $divisible = false For $number In $primes If Mod($i, $number) = 0 Then $divisible = true ExitLoop EndIf Next if $divisible = false Then _ArrayAdd($primes, $i) $output &= $i EndIf Next MsgBox(0,'',UBound($primes)) Well, except the timing functions which I decided there's no reason to add after I ran it lol , would you say this code is equivalent ? It returns the same number of results (plus one, I guess it's the initialization I had to use ?) so I guess it runs fine. EDIT: AutoIt code tag my ass .... Edited October 22, 2012 by Inverted Share this post Link to post Share on other sites
JohnOne 1,603 Posted October 22, 2012 I don't know much about maths, but I believe prime numbers can only be odd so it makes no sense to test even numbers, also it will half the speed. AutoIt Absolute Beginners Require a serial Pause Script Video Tutorials by Morthawt ipify Monkey's are, like, natures humans. Share this post Link to post Share on other sites
jchd 1,506 Posted October 22, 2012 Well, except 2 This wonderful site allows debugging and testing regular expressions (many flavors available). An absolute must have in your bookmarks.Another excellent RegExp tutorial. Don't forget downloading your copy of up-to-date pcretest.exe and pcregrep.exe hereRegExp tutorial: enough to get startedPCRE v8.33 regexp documentation latest available release and currently implemented in AutoIt beta.SQLitespeed is another feature-rich premier SQLite manager (includes import/export). Well worth a try.SQLite Expert (freeware Personal Edition or payware Pro version) is a very useful SQLite database manager.An excellent eBook covering almost every aspect of SQLite3: a must-read for anyone doing serious work.SQL tutorial (covers "generic" SQL, but most of it applies to SQLite as well)A work-in-progress SQLite3 tutorial. Don't miss other LxyzTHW pages!SQLite official website with full documentation (may be newer than the SQLite library that comes standard with AutoIt) Share this post Link to post Share on other sites
Inverted 5 Posted October 23, 2012 I guess setting step to 2 would be a good start, but what matters, is that the algorithm is as much the same as possible, for comparison's sake. If I understanf correctly, constantly using ArrayAdd is the main performance hog, because it has to ReDim the array ? Or am I wrong ? What is a more efficient alternative to the way I do the array operations ? Share this post Link to post Share on other sites
Melba23 3,397 Posted October 23, 2012 Inverted,What is a more efficient alternative to the way I do the array operations ?Take a look at the last example in the Recursion tutorial in the Wiki and the text beneath it. M23 1 Inverted reacted to this Any of my own code posted anywhere on the forum is available for use by others without any restriction of any kind Open spoiler to see my UDFs: Spoiler ArrayMultiColSort ---- Sort arrays on multiple columnsChooseFileFolder ---- Single and multiple selections from specified path treeview listingDate_Time_Convert -- Easily convert date/time formats, including the language usedExtMsgBox --------- A highly customisable replacement for MsgBoxGUIExtender -------- Extend and retract multiple sections within a GUIGUIFrame ---------- Subdivide GUIs into many adjustable framesGUIListViewEx ------- Insert, delete, move, drag, sort, edit and colour ListView itemsGUITreeViewEx ------ Check/clear parent and child checkboxes in a TreeViewMarquee ----------- Scrolling tickertape GUIsNoFocusLines ------- Remove the dotted focus lines from buttons, sliders, radios and checkboxesNotify ------------- Small notifications on the edge of the displayScrollbars ----------Automatically sized scrollbars with a single commandStringSize ---------- Automatically size controls to fit textToast -------------- Small GUIs which pop out of the notification area Share this post Link to post Share on other sites
Spiff59 54 Posted October 23, 2012 (edited) I'd think preallocating your array, and then a single redim at the end would be the way to go: #include <Array.au3> Local $max = 1000, $primes[100 + $max * .17] = [2], $idx For $i = 3 To $max Step 2 For $j = 0 to $idx $rem = Mod($i, $primes[$j]) If $rem = 0 Then ExitLoop Next If $rem Then $idx += 1 $primes[$idx] = $i EndIf Next ReDim $primes[$idx + 1] _ArrayDisplay($primes, $idx + 1 & " found") edit: trying to tune the preallocated array size Edited October 23, 2012 by Spiff59 Share this post Link to post Share on other sites