Space - Katie

lib/array_intersection.rb

@@ -1,3 +1,10 @@
 def intersection(list1, list2)
-  raise NotImplementedError, "Intersection not implemented"
-end
+  common_items = []
+  list1.each do |item|
+    if common_items.include?(item) == false && list2.include?(item) == true
+      common_items.push(item)
+    end
+  end
+  return common_items
+
+end

lib/palindrome_permutation.rb

@@ -1,4 +1,14 @@
 
 def palindrome_permutation?(string)
-  raise NotImplementedError, "palindrome_permutation? not implemented"
+  string_array = string.split("")
+  hash_of_letters = {}
+  string_array.each do |letter|
+    if hash_of_letters.keys.include?(letter)
+      hash_of_letters[letter] += 1
+    else
+      hash_of_letters[letter] = 1
+    end
+  end
+  return true if hash_of_letters.select { |letter,value| value%2 != 0}.keys.length <= 1
+  return false
 end

lib/permutations.rb

@@ -1,4 +1,25 @@
 
 def permutations?(string1, string2)
-  raise NotImplementedError, "permutations? not implemented"
-end
+  string1_array = string1.split("")
+  string2_array = string2.split("")
+  hash_of_letters = {}
+
+  string1_array.each do |letter|
+    if hash_of_letters.keys.include?(letter)
+      hash_of_letters[letter] += 1
+    else
+      hash_of_letters[letter] = 1
+    end
+  end
+
+  string2_array.each do |letter|
+    if hash_of_letters.keys.include?(letter)
+      hash_of_letters[letter] -= 1
+    else
+      return false
+    end
+  end
+
+  return true if hash_of_letters.select { |letter,value| value != 0}.keys.length == 0
+  return false
+end

test/palindrome_permutation_test.rb

@@ -1,6 +1,6 @@
 require_relative "test_helper"
 
-xdescribe "palindrome_permutation?" do
+describe "palindrome_permutation?" do
   it "will work for hello" do
     expect(palindrome_permutation?("hello")).must_equal false
   end

test/permutations_test.rb

@@ -1,6 +1,6 @@
 require_relative "test_helper"
 
-xdescribe "permutations?" do
+describe "permutations?" do
   it "returns true for empty string" do
     expect(permutations?("", "")).must_equal true
   end