YouTube URL algorithm?

Question

How would you go about generating the unique video URL\'s that YouTube uses?

Example:

• http://www.youtube.com/watch?v=CvUN8qg9lsk

Answer 1

I suggest using a perfect hash function:

Perfect Hash Function for Human Readable Order Codes

As the accepted answer indicates, take a number, then apply a sequence of "bijective" (or reversible) operations on the number to get a hashed number.

The input numbers should be in sequence: 0, 1, 2, 3, and so on.