Beefy Boxes and Bandwidth Generously Provided by pair Networks
The stupid question is the question not asked
 
PerlMonks  

Re: Use hashes instead of grep

by ColonelPanic (Friar)
on Nov 15, 2012 at 10:22 UTC ( #1003985=note: print w/ replies, xml ) Need Help??


in reply to Use hashes instead of grep
in thread How to grep exact string

I agree that, all else being equal, this would be the best design.

However, it ultimately depends on what the rest of the code does.



When's the last time you used duct tape on a duct? --Larry Wall


Comment on Re: Use hashes instead of grep
Re^2: Use hashes instead of grep
by space_monk (Chaplain) on Nov 15, 2012 at 10:55 UTC
    Not really. Even if the code uses both arrays then there is nothing preventing building a temporary hash through
    my %hash = map { $_ => 1 } @first_list;
    ..and then discarding the hash after the check for new machines. More likely is that he is only interested in the second list, or just new machines, and they could be in an array just like before.
    A Monk aims to give answers to those who have none, and to learn from those who know more.
      Yes, but this method is not clearly superior if arrays are needed for other purposes. The array comparison is simpler, uses less memory, and will be fast unless both files are huge.



      When's the last time you used duct tape on a duct? --Larry Wall
        The code to implement the hash version isn't significantly more complex - see the version in another nodelet for how it would go.
        A Monk aims to give answers to those who have none, and to learn from those who know more.

        Or, as Darth put it:

        The time to build the structure is insignificant compared to the power of the hash!

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://1003985]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others taking refuge in the Monastery: (7)
As of 2014-10-25 12:24 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    For retirement, I am banking on:










    Results (143 votes), past polls