anrieff

#!/usr/bin/python

""" Compute the probability of M people sharing a birthday out of a group of
    N people.

    The parameter `exact' determines whether we want to ignore clusterings of
    more than M people with the same birthday (thus the largest group of 
    coincident birthdays is exactly M). If it's false, we allow "M or more".

    How it works: we define a recursive counting function