Good algorithm for combining items from N lists into one with balanced distribution?

Question

Let\'s say I have the three following lists

A1
A2
A3

B1
B2

C1
C2
C3
C4
C5

I\'d like to combine them into a si

Answer 1

I'm thinking of a divide and conquer approach. Each iteration of which you split all the lists with elements > 1 in half and recurse. When you get to a point where all the lists except one are of one element you can randomly combine them, pop up a level and randomly combine the lists removed from that frame where the length was one... et cetera.

Something like the following is what I'm thinking:

- filter lists into three categories
    - lists of length 1
    - first half of the elements of lists with > 1 elements
    - second half of the elements of lists with > 1 elements
- recurse on the first and second half of the lists if they have > 1 element
    - combine results of above computation in order
- randomly combine the list of singletons into returned list