Ah Hah! Thanks tilly ++. Because it was described as a `homework' problem I thought I'd be able to come up with something without looking `in the back of the book'.

However after a few scribbles (and my Camel and Cookbook are at work, and I'm not) I came to a grinding halt.

Looking at particle's solution made me realise I should have been able to think it through to that type of solution and I didn't actually pick it as `breaking the rules'.

However your points are very well made... when you've got the RE `hammer' every string problem looks like a nail! Once I understood this, I looked for a different approach.

This approach would involve using a hash, splitting the string into digits, counting the unique keys and checking for any with a count (value) more than one. Now that's a homework problem I can handle 8-).

Thanks for insight. hagen

In reply to Re: Re (tilly) 1: regexp golf - homework by hagen
in thread regexp golf - homework by Boots111

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