Like drawing out of a hat, but better!

secret-santa.rb

# list of people to secret santa
names = ['Foo', 'Bar', 'John', 'Jim']

raise 'not even!' if names.count % 2 != 0

def assigned?(matches, person)
  matched_people = matches.values
  matched_people.include? person
end

matches = {}
names.each do |name|
  assignee = name

  while assignee == name do
    assignee = names.sample

    while assigned?(matches, assignee)
      assignee = names.sample
    end
  end

  matches[name] = assignee
end

puts matches.inspect