Quite complicated, isn't it? As physi already stated, a simple: 
s/((.)\2*)\1/$1/g

[download]
will do the trick of half-ing each repeated occurence and rounding them up. So "aaabbbb" will become "aabb".

In reply to Re: Replacing with multiple occurrences. by Skeeve
in thread Replacing with multiple occurrences. by maithree

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