My current code involves a hash which counts occurrences of groups of characters.

So, for example:

%freq = {
    aaa => 5,
    aab => 2, 
    aac => 8,
    aad => 7,
    ...
    etc.
}

[download]

However, rather than being hard coded the letter groups are generated by my script, and could potentially be any ASCII character, rather than just alphabetical.

What I need to do is find all the keys starting with a given string (such as 'aa' in the above example). So far the only way I've been able to come up with is sorting the result of the keys() and then just running through the relevant slice of the array, which could take a very long time (potentially 2^40 entries if I'm unlucky), and it just seems there has to be a better way to do this.

Thanks in advance.

In reply to Hash entries starting with a given string. by SwiftEagle

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