Quickest way to search a large list of strings (with wildcard functionality)

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Hello,

I'm currently looking to provide a way for users to search a large list of strings (at least 400,000) using wildcards and possibly provide auto completion (this is not essential).

Something like

*test

Would return all the strings that end in "test" for example.

I've investigated looking into different types of searches including a trie setup, but I can't tell if these provide wildcard functionality or if they need an actual prefix to work with?

A few source code examples I've downloaded seem to require a prefix.

Any advice would be greatly appreciated.

Thanks

Posted 10-Mar-14 5:16am

sHoE_FeRReT

Updated 10-Mar-14 5:33am

v2

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Sergey Alexandrovich Kryukov 10-Mar-14 11:44am

Why wildcards? Maybe Regular Expressions would be better? At least, they are already implemented...
—SA

sHoE_FeRReT 10-Mar-14 12:12pm

We need wildcards to search for strings that end with particular patterns. I tried a LINQ with a regular expression to create the wildcard functionality, this worked fine unless the first character was a wildcard. something like "t*est" would return results quickly, but "*test" could take upto around 10 seconds.

Sergey Alexandrovich Kryukov 10-Mar-14 14:54pm

Do you understand that Regular Expression is a big generalization over primitive wildcard approach? Absolutely everything you could do with wildcards, you can do with Regex. If you could not implement something, it simply means that you did it wrong. :-)
—SA

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Mehdi Gholam · Accepted Answer · 2014-03-10T07:31:00

Solution 1

You need to create inverted indexes or use a component like lucene : https://lucenenet.apache.org/[^]

or my article hOOt : hOOt - full text search engine[^]

Posted 10-Mar-14 7:31am

Mehdi Gholam

Comments

Maciej Los 10-Mar-14 14:15pm

The second one link is the best! ;)
+5!

Mehdi Gholam 11-Mar-14 2:33am

Codeproject articles rock! :)

Sergey Alexandrovich Kryukov 10-Mar-14 14:54pm

Absolutely, a 5.
—SA

Mehdi Gholam 11-Mar-14 2:33am

Cheers Sergey!

Maciej Los · Accepted Answer · 2014-03-10T08:14:00

Solution 2

Please, read Sergey's comment to the question and follow below links:
How to: Search Strings Using String Methods (C# Programming Guide)[^]
How to: Search Strings Using Regular Expressions (C# Programming Guide)[^]

Posted 10-Mar-14 8:14am

Maciej Los

Comments

Sergey Alexandrovich Kryukov 10-Mar-14 14:56pm

Very good, thank you for complementing my idea, a 5.
Look at the OP's comment to my comment to the question. It looks like she/he wouldn't mind Regex but failed to use it correctly...
—SA

Maciej Los 10-Mar-14 15:01pm

Thank you, Sergey ;)
I saw OP's comments. What can i say? It happens ;)

Sergey Alexandrovich Kryukov 10-Mar-14 15:06pm

:-)
...oh, I mean, :-(
—SA

Mehdi Gholam 11-Mar-14 2:34am

My 5 also!

Maciej Los 11-Mar-14 16:08pm

Thank you, Mehdi ;)