hamming recursive

hamming.rb

@@ -0,0 +1,36 @@
+class Hamming
+
+  def self.compute(seq1,seq2)
+    unless seq1.length == seq2.length
+      raise ArgumentError.new("The lengths of the strands must be equal.")
+    end
+
+    @array1 = seq1.split(//)
+    @array2 = seq2.split(//)
+    @count = 0
+    next_elements
+    count_differences(@element1,@element2)
+  end
+
+  def self.count_differences(element1,element2)
+    if @element1 == nil
+      return @count
+    end
+
+    if element1 != element2
+      @count += 1
+      next_elements
+      count_differences(@element1,@element2)
+    else
+      @count += 0
+      next_elements
+      count_differences(@element1,@element2)
+    end
+  end
+
+  def self.next_elements
+    @element1 = @array1.shift
+    @element2 = @array2.shift
+  end
+
+end

hamming_test.rb

@@ -4,72 +4,58 @@
 
 class HammingTest < Minitest::Test
   def test_identical_strands
-    skip
     assert_equal 0, Hamming.compute('A', 'A')
   end
 
   def test_long_identical_strands
-    skip
     assert_equal 0, Hamming.compute('GGACTGA', 'GGACTGA')
   end
 
   def test_complete_distance_in_single_nucleotide_strands
-    skip
     assert_equal 1, Hamming.compute('A', 'G')
   end
 
   def test_complete_distance_in_small_strands
-    skip
     assert_equal 2, Hamming.compute('AG', 'CT')
   end
 
   def test_small_distance_in_small_strands
-    skip
     assert_equal 1, Hamming.compute('AT', 'CT')
   end
 
   def test_small_distance
-    skip
     assert_equal 1, Hamming.compute('GGACG', 'GGTCG')
   end
 
   def test_small_distance_in_long_strands
-    skip
     assert_equal 2, Hamming.compute('ACCAGGG', 'ACTATGG')
   end
 
   def test_non_unique_character_in_first_strand
-    skip
     assert_equal 1, Hamming.compute('AGA', 'AGG')
   end
 
   def test_non_unique_character_in_second_strand
-    skip
     assert_equal 1, Hamming.compute('AGG', 'AGA')
   end
 
   def test_large_distance
-    skip
     assert_equal 4, Hamming.compute('GATACA', 'GCATAA')
   end
 
   def test_large_distance_in_off_by_one_strand
-    skip
     assert_equal 9, Hamming.compute('GGACGGATTCTG', 'AGGACGGATTCT')
   end
 
   def test_empty_strands
-    skip
     assert_equal 0, Hamming.compute('', '')
   end
 
   def test_disallow_first_strand_longer
-    skip
     assert_raises(ArgumentError) { Hamming.compute('AATG', 'AAA') }
   end
 
   def test_disallow_second_strand_longer
-    skip
     assert_raises(ArgumentError) { Hamming.compute('ATA', 'AGTG') }
   end
 end