justincampbell/unique_combinations.rb

## unique_combinations.rb
values = ["a", "b", "c"]

result = (1..values.length).inject([]) { |buffer, count|
  buffer |= values.combination(count).to_a
}.map(&:join)

result # => ["a", "b", "c", "ab", "ac", "bc", "abc"]
	values = ["a", "b", "c"]

	result = (1..values.length).inject([]) { \|buffer, count\|
	buffer \|= values.combination(count).to_a
	}.map(&:join)

	result # => ["a", "b", "c", "ab", "ac", "bc", "abc"]