number generator

[Steven D'Aprano]

On Tue, 13 Mar 2007 20:42:17 -0700, tleeuwenburg at gmail.com wrote:

> It should be possible to enumerate all sets of five numbers which sum
> to 50 and randomly select one of them.

Of course it's possible. It's also a very inefficient way of doing so. For
five numbers between 1 and 50, there are 50**5 = 312,500,000 possible sets
to enumerate. Do you really think it is a good idea to generate over three
hundred and twelve million lists, just to return one?

The sole advantage of this method is that it will give "the most random"
result, with the least amount of bias possible. But it isn't clear that
the much more efficient fence-post method is any less random.

See also the Subset Sum Problem:
http://en.wikipedia.org/wiki/Subset_sum_problem



-- 
Steven D'Aprano