title: What's the best way to hash a string vector not very long (urls)?
body: <p>I am now dealing with url classification. I partition url with "/?", etc, generating a bunch of parts. In the process, I need to hash the first part to the kth part, say, k=2, then for "http://stackoverflow.com/questions/ask", the key is a string vector "stackoverflow.com questions". Currently, the hash is like Hash. But it consumes a lot of memory. I wonder whether MD5 can help or are there other alternatives. In effect, I do not need to recover the key exactly, as long as differentiating different keys.
  Thanks!</p>