Code Golf: Duplicate Character Removal in String

Posted by Alex on Stack Overflow See other posts from Stack Overflow or by Alex
Published on 2009-08-27T23:57:50Z Indexed on 2011/01/10 12:53 UTC
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code-golf

The challenge: The shortest code, by character count, that detects and removes duplicate characters in a String. Removal includes ALL instances of the duplicated character (so if you find 3 n's, all three have to go), and original character order needs to be preserved.

Example Input 1:
nbHHkRvrXbvkn

Example Output 1:
RrX

Example Input 2:
nbHHkRbvnrXbvkn

Example Output 2:
RrX

(the second example removes letters that occur three times; some solutions have failed to account for this)

(This is based on my other question where I needed the fastest way to do this in C#, but I think it makes good Code Golf across languages.)

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