From 75973d59f1e0712c03f45e19ca8ecf650658783a Mon Sep 17 00:00:00 2001
From: "m.dove@live.com" <“m.dove@live.com”>
Date: Sun, 8 Dec 2019 23:59:12 -0800
Subject: [PATCH] Finished linked list methods

---
 lib/linked_list.rb       | 45 +++++++++++++++++++++++++++++++++++-----
 test/linked_list_test.rb | 38 +++++++++++++++------------------
 2 files changed, 57 insertions(+), 26 deletions(-)

diff --git a/lib/linked_list.rb b/lib/linked_list.rb
index 9e97557..9e879e2 100644
--- a/lib/linked_list.rb
+++ b/lib/linked_list.rb
@@ -1,4 +1,4 @@
-require_relative 'node'
+require_relative "node"
 
 class LinkedList
   attr_reader :head
@@ -10,36 +10,71 @@ def initialize
   # Time complexity - ?
   # Space complexity - ?
   def add_first(data)
-
+    @head = Node.new(data, @head)
   end
 
   # Time complexity - ?
   # Space complexity - ?
   def get_first
-
+    if @head.nil?
+      return nil
+    else
+      return @head.data
+    end
   end
 
   # Time complexity - ?
   # Space complexity - ?
   def length
-    return 0
+    count = 0
+    temp = @head
+    while temp != nil
+      count += 1
+      temp = temp.next
+    end
+    return count
   end
 
   # Time complexity - ?
   # Space complexity - ?
   def add_last(data)
+    temp = @head
+    while temp != nil && temp.next != nil
+      temp = temp.next
+    end
+    last_node = Node.new(data)
 
+    if (temp != nil)
+      temp.next = last_node
+    else
+      @head = last_node
+    end
   end
 
   # Time complexity - ?
   # Space complexity - ?
   def get_last
+    temp = @head
 
+    while temp != nil && temp.next != nil
+      temp = temp.next
+    end
+    return temp.data
   end
 
   # Time complexity - ?
   # Space complexity - ?
   def get_at_index(index)
-
+    temp = @head
+    count = 0
+    while count < index && temp != nil
+      temp = temp.next
+      count += 1
+    end
+    if (count == index)
+      return temp.data
+    else
+      return nil
+    end
   end
 end
diff --git a/test/linked_list_test.rb b/test/linked_list_test.rb
index 2a805c7..311e12d 100644
--- a/test/linked_list_test.rb
+++ b/test/linked_list_test.rb
@@ -1,9 +1,8 @@
-require 'minitest/autorun'
-require 'minitest/reporters'
+require "minitest/autorun"
+require "minitest/reporters"
 require "minitest/skip_dsl"
 
-require_relative '../lib/linked_list'
-
+require_relative "../lib/linked_list"
 
 Minitest::Reporters.use! Minitest::Reporters::SpecReporter.new
 
@@ -13,24 +12,24 @@
     @list = LinkedList.new
   end
 
-  describe 'initialize' do
-    it 'can be created' do
+  describe "initialize" do
+    it "can be created" do
 
       # Assert
       expect(@list).must_be_kind_of LinkedList
     end
   end
 
-  xdescribe 'add_first & get_first' do
-    it 'can add values to an empty list' do
+  describe "add_first & get_first" do
+    it "can add values to an empty list" do
       # Act
-        @list.add_first(3)
+      @list.add_first(3)
 
-        # Assert
-        expect(@list.get_first).must_equal 3
+      # Assert
+      expect(@list.get_first).must_equal 3
     end
 
-    it 'will put the last added item to the front of the list' do
+    it "will put the last added item to the front of the list" do
       # Act
       @list.add_first(1)
       @list.add_first(2)
@@ -45,13 +44,12 @@
       expect(@list.get_first).must_equal 3
     end
 
-    it 'will return `nil` for `getFirst` if the list is empty' do
-
+    it "will return `nil` for `getFirst` if the list is empty" do
       expect(@list.get_first).must_be_nil
     end
   end
 
-  xdescribe "length" do
+  describe "length" do
     it "will return 0 for an empty list" do
       expect(@list.length).must_equal 0
     end
@@ -66,7 +64,7 @@
     end
   end
 
-  xdescribe "addLast & getLast" do
+  describe "addLast & getLast" do
     it "will add to the front if the list is empty" do
       @list.add_last(1)
       expect(@list.get_first).must_equal 1
@@ -86,17 +84,15 @@
       expect(@list.get_first).must_equal 2
       expect(@list.get_last).must_equal 4
       expect(@list.length).must_equal 3
-
     end
-
   end
 
-  xdescribe 'get_at_index' do
-    it 'returns nil if the index is outside the bounds of the list' do
+  describe "get_at_index" do
+    it "returns nil if the index is outside the bounds of the list" do
       expect(@list.get_at_index(3)).must_be_nil
     end
 
-    it 'can retrieve an item at an index in the list' do
+    it "can retrieve an item at an index in the list" do
       @list.add_first(1)
       @list.add_first(2)
       @list.add_first(3)