# overlapping sets

kpp9c kp8 at mac.com
Fri Mar 24 07:55:43 CET 2006

```I have a question... and ... whew ... i am gonna be honest, i haven't
the slightest clue how to even start ... i am not sure if i used up all
my good will here or can take a mulligan.. i love to try to at least
post some lame broken code of my own at first... but like i said, not
being a math person i am not even sure how to start or if it is even
possible.

here's the deal... i have a dictionary that defines some collections..
like so:

sets = { ('one') : [0, 4, 7, 9 ],
('two') : [0, 3, 7, 9 ],
('three') : [0, 4, 7, 11],
('four') : [0, 3, 7, 10 ],
('five') : [0, 4, 7, 10 ],
('six') : [0, 4, 8, 10 ],
('seven') : [0, 3, 6, 10],
('eight') : [0, 3, 6, 9 ],
('nine') : [0, 3, 7, 11 ],
('ten') : [0, 5, 7, 10 ] }

I every time i call this function i would like like it to return a
collection at random, any collection, so long as it has all but one
element that is the same. So if i grab [0, 4, 7, 9 ] as my first set
my next set could be: [0, 3, 7, 9 ], or [0, 4, 8, 9 ], or [0, 4, 7,
10], or [1, 4, 7, 9 ], since all these sets contain 3 elements in
common with the first, and only one that is new or different... but if
my first run give me: [0, 4, 7, 9 ] i would not get [0, 5, 7, 10 ],
since this is set has 2 elements that are unique. The goal it to move
from set to set to set to set always with a maximum of overlap & common
elements.

I wonder, if this is even possible, *and* if it can be done with sets
that have as many as 7, 8, or even 9 elements or if this would be too
slow to even attempt.

cheers,

kp8

[for the record using python 2.3 on a macintosh at the moment]

```