Water - Mackenzie

lib/queue.rb

@@ -1,31 +1,74 @@
 class Queue
 
+MAX_SIZE = 20
+
   def initialize
     # @store = ...
-    raise NotImplementedError, "Not yet implemented"
+    # raise NotImplementedError, "Not yet implemented"
+
+    @store = Array.new(MAX_SIZE)
+    @front = -1 
+    @back = -1
   end
 
   def enqueue(element)
-    raise NotImplementedError, "Not yet implemented"
+    # raise NotImplementedError, "Not yet implemented"
+
+    if (@front == 0 && @back == MAX_SIZE - 1) || (@back == (@front - 1) % MAX_SIZE - 1)
+      raise ArgumentError.new, "Queue is full"
+    elsif @front == -1 && @back == -1
+      @front = 0
+      @back = 0
+    elsif @back == MAX_SIZE 
+      @back = 0
+    else 
+      @back += 1
+    end
+
+    @store[@back] = element
+
   end
 
   def dequeue
-    raise NotImplementedError, "Not yet implemented"
+    # raise NotImplementedError, "Not yet implemented"
+
+    if @store.empty?
+      raise ArgumentError.new, "Queue is empty"
+    end
+
+    data = @store[@front]
+    @store[@front] = nil 
+
+
+    if (@front == @back)
+      @front == -1
+      @back == -1 
+    elsif (@front == MAX_SIZE - 1) 
+      @front = 0
+    else 
+      @front += 1
+    end 
+
+    return data
+
   end
 
   def front
-    raise NotImplementedError, "Not yet implemented"
+    # raise NotImplementedError, "Not yet implemented"
+    return @store[@front]
   end
 
   def size
-    raise NotImplementedError, "Not yet implemented"
+    # raise NotImplementedError, "Not yet implemented"
+    return @store.compact.length
   end
 
   def empty?
-    raise NotImplementedError, "Not yet implemented"
+    # raise NotImplementedError, "Not yet implemented"
+    return @store.compact.length == 0 ? true : false
   end
 
   def to_s
-    return @store.to_s
+    return @store.compact.to_s
   end
 end

lib/stack.rb

@@ -1,19 +1,23 @@
 class Stack
   def initialize
     # @store = ...
-    raise NotImplementedError, "Not yet implemented"
+    @store = LinkedList.new
   end
 
   def push(element)
-    raise NotImplementedError, "Not yet implemented"
+    @store.add_first(element)
   end
 
   def pop
-    raise NotImplementedError, "Not yet implemented"
+    return nil if self.empty?
+
+    item = @store.remove_first
+
+    return item
   end
 
   def empty?
-    raise NotImplementedError, "Not yet implemented"
+    return @store.empty?
   end
 
   def to_s