Beefy Boxes and Bandwidth Generously Provided by pair Networks
laziness, impatience, and hubris
 
PerlMonks  

Re^3: Finding an intersection of two sets, lean and mean

by Sinister (Friar)
on Jun 29, 2005 at 14:52 UTC ( #471044=note: print w/ replies, xml ) Need Help??


in reply to Re^2: Finding an intersection of two sets, lean and mean
in thread Finding an intersection of two sets, lean and mean

Found it!

Perhaps you meant 'grep' instead of 'map' ?? ;->

This gives a different result set then mine (larger in every case), but this could be a problem with my code...

It is faster, untill the sets become a teeny weeny bit bigger (eg: +5M lines)


Comment on Re^3: Finding an intersection of two sets, lean and mean
Re^4: Finding an intersection of two sets, lean and mean
by dragonchild (Archbishop) on Jun 29, 2005 at 15:00 UTC
    Yes, grep is the correct operator, not map. See - I did bork my code. :-)

    As for the +5M lines thing - that becomes a function of your available RAM. Your string solution will hit the same limit, but at around 20-30M (if 5M is your limit with hashes).

    Note, your code to build the hash string will bomb faster than your code to iterate through it because you use foreach instead of while to iterate through the list. This creates a copy of the list you're foreach'ing through whereas while does not.


    My criteria for good software:
    1. Does it work?
    2. Can someone else come in, make a change, and be reasonably certain no bugs were introduced?

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://471044]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others surveying the Monastery: (8)
As of 2014-07-26 18:08 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    My favorite superfluous repetitious redundant duplicative phrase is:









    Results (178 votes), past polls