Question

I’m looking to remove duplicate phrases from any give string.

Example:

My_First_Post_My_First_Post.htm

Would have the phrase “My_First_Post” in there twice, thus becoming:

My_First_Post_.htm

Any easy way to do this?

Answer 1

You can try regular expressions – careful about efficiency for sure, though:

Regex re = new Regex(@"(?<m>(.+))(.*?)\k<m>", RegexOptions.Compiled);
string str = "My_First_Post_My_First_Post.htm";

re.Replace(str, "$1$2"); // My_First_Post_.htm

It removes the first, longest, repeated sequence. To make it at least 10 characters, e.g., change the first group to:

(?<m>(.{10,}))

To restrict the distance between characters to 2, e.g., change the second group to:

(.{,2}?)

For 1 character, just put (.??).