How can I remove repeated characters but leave two of them?

Question

If there are more than 2 characters "Hiiiiiii My frieeend!!!!!!!"

I need to be reduced to "Hii My frieend!!"

Please undestand that in my language there are many words with double chars. Thnx in advance

kplla

Answer 1

Perl / regex (and if it's not english, Perl has given me better luck with Unicode than PHP):

#!/usr/bin/perl

$str = "Hiiiiii My Frieeeeend!!!!!!!";

$str =~ s/(.)\1\1+/$1$1/g;

print $str;

Answer 2

Here's another regex solution that uses lookahead (just for fun), in Java:

System.out.println(
    "Hiiiiii My Frieeeeend!!!!!!!".replaceAll("(.)(?=\\1\\1)", "")
); // prints "Hii My Frieend!!"