Here's a problem my tired brain is having trouble with.

Given a sorted array of integers, convert them into as many
ranges as possible (ranges of three or more).

Example:
[1,2,3,4,6,7,8,11,12,15,16,17] ==> [1..4,6..8,11,12,15..17]

How would *you* do this?


Thanks,
Hal