gistfile1.txt

Bonus: subsets

Attempt this after you have the other two problems working.

Write a method that, given an array of unique items, finds all the subsets of items:

subsets(["a", "b", "c"]) == [
  [], # note that the empty set counts!
  ["a"], ["a", "b"], ["a", "b", "c"], ["a", "c"]
  ["b"], ["b", "c"],
  ["c"]
]