Regexp Homework :-)

From: Simon Brown (simon.brown_at_[hidden])
Date: 2003-05-01 06:52:11

A few days ago I received great help with a regexp question - now here's
another which I doubt can be done.

Question: if the text string contains three words AAA BBB AAA then return
the string (if any) which is repeated two or three times.

Examples:
AAA AAA AAA return AAA
AAA BBB AAA return AAA
AAA AAA BBB return AAA
AAA BBB CCC return <nothing>

Can this be done with a regular expression?

And a very, very big thanks to those who wrote regexp, you have no idea how
useful it is for me :-)

Simon Brown, Casa Bergenia, CH-7031 Laax
www.hb9drv.ch