[Closed] Bsearch to replace finditem with huge array?

here is a fast reference, I use stringstream to build a 500000 elements string , with 100000 matched , less than 3000ms , I insert 100 other strings , less than 400ms , test on max 2021

(
	aa=#(
	@"C:\Users\Administrator\Personal",
	@"C:\Users\Administrator\Personal\3ds Max 2020",
	@"C:\Users\Administrator\Personal\3ds Max 2021",
	@"C:\Users\Administrator\Personal\3dsMax",
	@"C:\Users\Administrator\Personal\Apowersoft",
	@"C:\Users\Administrator\Personal\Apowersoft",
	@"C:\Users\Administrator\Personal\Autodesk Application Manager",
	@"C:\Users\Administrator\Personal\WeChat Files",
	@"C:\Users\Administrator\Personal\WeChat Files\test.max",
	@"C:\Users\Administrator\Personal\Windows Live"
)
global cc=""
for j = 1 to 10 do cc+=substituteString aa[j] "\\" "/"+","
	fn test5d =
	(
		local ss = stringstream"",fmt ="%"
		for i = 1 to 1000 do format fmt cc to:ss  -- for 500000 elements , set i = 1 to 50000 , if use old version max , may very slow
		ss as string
	)
	st = timestamp()
	global bb = test5d()
	format "Build Time: %ms\n" (timestamp()-st)
	aa
)
(
	st = timestamp()
	findstrings=@"C:\Users\Administrator\Personal\WeChat Files"
	ss=dotNetObject "System.Text.RegularExpressions.Regex" "" (dotnetclass "System.Text.RegularExpressions.RegexOptions").IgnoreCase
	dd=ss.Split bb (substituteString findstrings "\\" "/")
	sel=#()  -- if just need the count , no need below , the time will hundreds ms with 500000 elements , the count is dd.count - 1
	ss1 = stringstream""
	for i = 2 to dd.count  do format  (findstrings + (substituteString (substring dd[i] 1 (ss.Match dd[i] ",").Index)  "/" "\\") + ",") to:ss1
	sel=ss.split ss1 ","
	deleteitem sel sel.count
	format "Search Time: %ms\n" (timestamp()-st)
	sel.count
)

It seems too complex…

Thanks for the code,I tried on old version,3ds max 2013,

500000 elements string:

Build Time: 121261ms
Search Time: 11569ms

I will try all code in this post,thanks for all

I use a .dll file read all files and folders of a driver such as D:,then I want to count some directories or files which I need,all directories or files stored in a big array,that’s why I need a fastest way to do this job.

In order to use bsearch() you first need to sort the array, and that will be a killer, moreover if you use qsort().

I don’t think this is a good case for using bsearch().

This takes just 188ms for 500K items in an unsorted array, which in my opinion is pretty fast.

(
	fn FindStringInArray arr str =
	(
		str += "*"
		count=0
		
		for i in arr where matchpattern i pattern:str do count+=1
		
		return count
	)
)

What is your performance goal?

this is exactly what I showed above … I don’t see performance issues either

OK,I did a test,it’s really fast,the matchpattern is the best solution,thank you all again.