linked list methods working.

array-list.rb

@@ -2,25 +2,53 @@
 
 class ArrayList
   def initialize
-    @storage = []
+    @storage = [nil,nil,nil,nil,nil]
+    @size = 0
+    # capacity is 5 - but content is 0. there isn't anything occupying the available memory.
   end
 
   def add(value)
+    @storage[@size] = value
+    @size += 1
   end
 
-  def delete(value)
+  # always deletes last value in collection
+  def delete
+    @size -= 1
+    # ignore the last spot/ decrease the size by 1/ "ignore this item"
   end
 
   def display
+    @size.times do |i|
+       puts @storage[i]
+    end
   end
 
   def include?(key)
+    @size.times do |i|
+      if @storage[i] == key
+        return true
+      end
+    return false
   end
 
   def size
+    @size
   end
 
   def max
+    return nil if empty?
+    biggest = 0
+    @size.times do |i|
+      if @storage[i] > @storage[biggest]
+        biggest = i
+      end
+    end
+    @storage[biggest]
+  end
+
+  def empty?
+    @size == 0
   end
 
 end

linked-list.rb

@@ -1,100 +1,129 @@
-# Quick Example of a Self Referential Data Structure in Ruby
-# NODE -> contains a value and a pointer to (next_node)
-# LinkedList -> This class holds the linked list functions - adding a node, traversing and displaying the linked list
-
-class Node
-   attr_accessor :value, :next_node
-
-   def initialize(val,next_in_line=null)
-       @value = val
-       @next_nodex = next_in_line
-       puts "Initialized a Node with value:  " + value.to_s
-   end
-end
-
-class LinkedList
-   def initialize(val)
-       # Initialize a new node at the head
-       @head = Node.new(val,nil)
-   end
-
-   def add(value)
-       # Traverse to the end of the list
-       # And insert a new node over there with the specified value
-       current = @head
-       while current.next_node != nil
-           current = current.next_node
-       end
-       current.next_node = Node.new(value,nil)
-       self
-   end
-
-   def delete(val)
+  # Quick Example of a Self Referential Data Structure in Ruby
+  # NODE -> contains a value and a pointer to (next_node)
+  # LinkedList -> This class holds the linked list functions - adding a node, traversing and displaying the linked list
+
+  class Node
+     attr_accessor :value, :next_node
+
+     def initialize(val,next_in_line = nil)
+         @value = val
+         @next_node = next_in_line
+         puts "Initialized a Node with value:  " + value.to_s
+     end
+  end
+
+  class LinkedList
+    attr_accessor :head
+     def initialize(val)
+         # Initialize a new node at the head
+         @head = Node.new(val,nil)
+     end
+
+     def add(value)
+         # Traverse to the end of the list
+         # And insert a new node over there with the specified value
+         current = @head
+         while current.next_node != nil
+             current = current.next_node
+         end
+         current.next_node = Node.new(value,nil)
+         self
+     end
+
+     def delete(val)
+         current = @head
+         if current.value == val
+             # If the head is the element to be delete, the head needs to be updated
+             @head = @head.next_node
+         else
+             # ... x -> y -> z
+             # Suppose y is the value to be deleted, you need to reshape the above list to :
+             #   ... x->z
+             # ( and z is basically y.next_node )
+             current = @head
+             while (current != nil) && (current.next_node != nil) && ((current.next_node).value != val)
+                 current = current.next_node
+             end
+
+             if (current != nil) && (current.next_node != nil)
+                 current.next_node = (current.next_node).next_node
+             end
+         end
+     end
+
+     def display
+         # Traverse through the list till you hit the "nil" at the end
+         current = @head
+         full_list = []
+         while current.next_node != nil
+             full_list += [current.value.to_s]
+             current = current.next_node
+         end
+         full_list += [current.value.to_s]
+         puts full_list.join("->")
+     end
+
+    def include?(key)
+      current = @head
+      until current == nil
+        if current.value == key
+          return true
+        else
+          current = current.next_node
+        end
+      end
+      false
+    end
+
+     def size
        current = @head
-       if current.value == val
-           # If the head is the element to be delete, the head needs to be updated
-           @head = @head.next_node
-       else
-           # ... x -> y -> z
-           # Suppose y is the value to be deleted, you need to reshape the above list to :
-           #   ... x->z
-           # ( and z is basically y.next_node )
-           current = @head
-           while (current != nil) && (current.next_node != nil) && ((current.next_node).value != val)
-               current = current.next_node
-           end
-
-           if (current != nil) && (current.next_node != nil)
-               current.next_node = (current.next_node).next_node
-           end
+       acc = 0
+       until current == nil
+         current = current.next_node
+         acc += 1
        end
-   end
+       acc
+     end
 
-   def display
-       # Traverse through the list till you hit the "nil" at the end
+     def max
        current = @head
-       full_list = []
-       while current.next_node != nil
-           full_list += [current.value.to_s]
+       max = 0
+       until current == nil
+         if current.value > max
+           max = current.value
+           current = current.next_node
+         else
            current = current.next_node
+         end
        end
-       full_list += [current.value.to_s]
-       puts full_list.join("->")
-   end
-
-   def include?(key)
-   end
-
-   def size
-   end
-
-   def max
-   end
-
-end
-
-# Initializing a Linked List with a node containing value (5)
-ll = LinkedList.new(5)
-
-# Adding Elements to Linked List
-ll.add(10)
-ll.add(20)
-
-# Display the Linked List
-puts "Displaying Linked List:"
-ll.display
-
-puts "Delete 10 and then display the linked list:"
-ll.delete(10)
-ll.display
-
-=begin
-Output:
-Initialized a Node with value:  5
-Initialized a Node with value:  10
-Initialized a Node with value:  20
-Displaying Linked List:
-5->10->20
-Delete 10 and then display the linked list:
-5->20
-=end
+       max
+     end
+
+  end
+
+  # Initializing a Linked List with a node containing value (5)
+  # ll = LinkedList.new(5)
+  #
+  # # Adding Elements to Linked List
+  # ll = LinkedList.new(5)
+  # ll.add(10)
+  # ll.add(20)
+  #
+  # # Display the Linked List
+  # puts "Displaying Linked List:"
+  # ll.display
+  #
+  # puts "Delete 10 and then display the linked list:"
+  # ll.delete(10)
+  # ll.display
+
+  # =begin
+  # Output:
+  # Initialized a Node with value:  5
+  # Initialized a Node with value:  10
+  # Initialized a Node with value:  20
+  # Displaying Linked List:
+  # 5->10->20
+  # Delete 10 and then display the linked list:
+  # 5->20
+  # =end