A good approach here would be to make a test case for NSArray and NSSet, a known set of files and simply test now long each takes.
On Apr 14, 2014, at 8:59 PM, Graham Cox wrote: > > On 15 Apr 2014, at 10:02 am, Varun Chandramohan > <varun.chandramo...@wontok.com> wrote: > >> Lets say I walkthrough 1000 files and folders, for each file/folder I need >> to compare against this array list. This might be slow or inefficient. Is >> there a faster way to do something like this? > > > As a general principle, if you have to check whether one of a list of things > is part of another list of things, an array is the wrong container for the > job, because it amounts to a worst-case O(n^2) search. Instead, use a set or > hash table for the set of things that must be detected among the first list, > and it reduces to a worst-case O(n) operation. That said, if the number of > items in the second list is small, the performance may be acceptable, and > using a hash table might not speed it up noticeably - the time will be > dominated by the iteration through the larger list. > > --Graham > > > > _______________________________________________ > > Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > > Please do not post admin requests or moderator comments to the list. > Contact the moderators at cocoa-dev-admins(at)lists.apple.com > > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/cocoa-dev/zav%40mac.com > > This email sent to z...@mac.com _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
