maximum.rb

require "test/unit"

class TestMaximum < Test::Unit::TestCase
  def maximum(arr)
    arr.length == 1 ? arr.first : arr.sort.last
  end

  def test_maximum
    assert_equal maximum([2, 42, 22, 02]), 42
    assert_equal maximum([-2, 0, 33, 304, 2, -2]), 304
    assert_equal maximum([1]), 1
  end
end