Perl-Sensitive Sunglasses | |
PerlMonks |
Re^4: CSV Cross Referencingby SuicideJunkie (Vicar) |
on Dec 03, 2014 at 18:43 UTC ( [id://1109152]=note: print w/replies, xml ) | Need Help?? |
That's essentially what the 2d hash does. $buckets->{latitude}{longitude}. You're only checking things with a similar latitude, and among those, only the things with a similar longitude. The upside is you don't need to loop. Instead of doing a latitude compare against everything, you immediately O(1) have the short list of things of the same latitude. Then instead of doing a compare against the longitudes of everything remaining, you immediately have the short list of things that match both.
In Section
Seekers of Perl Wisdom
|
|