From 26f78114a1be245364871940bba36005e6800391 Mon Sep 17 00:00:00 2001
From: Alex Robertson <arobertson335@gmail.com>
Date: Mon, 30 Mar 2020 18:27:28 -0700
Subject: [PATCH] Submitting Hashmap exercises.

---
 lib/array_intersection.rb           | 10 +++++++++-
 lib/palindrome_permutation.rb       | 26 ++++++++++++++++++++++++--
 lib/permutations.rb                 | 21 ++++++++++++++++++++-
 test/palindrome_permutation_test.rb |  2 +-
 test/permutations_test.rb           |  2 +-
 5 files changed, 55 insertions(+), 6 deletions(-)

diff --git a/lib/array_intersection.rb b/lib/array_intersection.rb
index ac8771f..dd60dc8 100644
--- a/lib/array_intersection.rb
+++ b/lib/array_intersection.rb
@@ -1,3 +1,11 @@
+# Time Complexity: O(n)
+# Space Complexity: O(n)
+
 def intersection(list1, list2)
-  raise NotImplementedError, "Intersection not implemented"
+  crossroads = []
+
+  list1.each do |n|
+    crossroads << n if list2.include?(n) != false
+  end 
+  return crossroads
 end
\ No newline at end of file
diff --git a/lib/palindrome_permutation.rb b/lib/palindrome_permutation.rb
index f113692..6c18aee 100644
--- a/lib/palindrome_permutation.rb
+++ b/lib/palindrome_permutation.rb
@@ -1,4 +1,26 @@
+# Time Complexity: O(n)
+# Space Complexity: O(n)
 
 def palindrome_permutation?(string)
-  raise NotImplementedError, "palindrome_permutation? not implemented"
-end
\ No newline at end of file
+  while string.empty? 
+    return true
+  end 
+
+  board = {}
+  letters = string.chars 
+  chalk = 0
+
+  letters.each do |c|
+    board[c] = 0
+  end
+
+  letters.each do |c|
+    if board[c]
+      board[c] += 1
+    end 
+    if board[c] % 2 == 0
+      chalk += 1
+    end
+  end 
+  return chalk == letters.length/2
+end 
\ No newline at end of file
diff --git a/lib/permutations.rb b/lib/permutations.rb
index 3b08381..ee60811 100644
--- a/lib/permutations.rb
+++ b/lib/permutations.rb
@@ -1,4 +1,23 @@
+# Time Complexity: O(n)
+# Space Complexity: O(n)
 
 def permutations?(string1, string2)
-  raise NotImplementedError, "permutations? not implemented"
+  if string1.length != string2.length 
+    return false
+  end 
+
+  perm = string1.chars
+  mutant = string2.chars 
+  mindflayer = {}
+
+  perm.each do |c|
+    mindflayer[c] = true
+  end 
+
+  mutant.each do |c|
+    if mindflayer[c] != true
+      return false
+    end 
+  end 
+  return true
 end
\ No newline at end of file
diff --git a/test/palindrome_permutation_test.rb b/test/palindrome_permutation_test.rb
index e9119de..984b333 100644
--- a/test/palindrome_permutation_test.rb
+++ b/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
diff --git a/test/permutations_test.rb b/test/permutations_test.rb
index 79da2f6..5f6ae77 100644
--- a/test/permutations_test.rb
+++ b/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