Fire-Blaine

lib/queue.rb

@@ -1,31 +1,69 @@
 class Queue
 
   def initialize
-    # @store = ...
-    raise NotImplementedError, "Not yet implemented"
+    @store = Array.new()
+    @max = 20
+    @front = 0
+    @back = 0
   end
 
   def enqueue(element)
-    raise NotImplementedError, "Not yet implemented"
+    if @back == @front-1 || (@front == 0 && @back == @max - 1)
+      # account for full Queue
+      return raise ArgumentError.new("Queue is full")
+    elsif self.empty?
+      @front = 0
+      @back = 0
+    elsif @back == @max-1
+      @back = 0 # if last then circles around
+    else 
+      @back = @back + 1 # incr by 1
+    end
+    @store[@back] = element
+
   end
 
   def dequeue
-    raise NotImplementedError, "Not yet implemented"
+    if self.empty?
+      raise ArgumentError.new("Queue's Empty") 
+    end
+
+    value = @store[@front]
+    @store[@front] = nil
+
+    if @front == @max - 1 # circle
+      @front = 0
+    else
+      @front = @front + 1
+    end
+    return value
   end
 
   def front
-    raise NotImplementedError, "Not yet implemented"
+    return @store[@front]
   end
 
   def size
-    raise NotImplementedError, "Not yet implemented"
+    return 0 if @front == -1
+    if @front < @back
+      @back - @front + 1
+    else
+      @max - (@back - @front)
+    end
   end
 
   def empty?
-    raise NotImplementedError, "Not yet implemented"
+    # return @front == -1
+    return @store.all?{ |e| e.nil? }
   end
 
   def to_s
-    return @store.to_s
+    list = []
+    index = @front
+    until index == @back + 1 
+      list << @store[index]
+      index = (index + 1) % @max
+    end
+    return list.to_s
   end
-end
+end

lib/stack.rb

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

test/queue_test.rb

@@ -10,7 +10,7 @@
   end
 
   it "adds something to an empty Queue" do
-    
+
     q = Queue.new
     q.enqueue(10)
     expect(q.to_s).must_equal "[10]"
@@ -22,6 +22,7 @@
     q.enqueue(10)
     q.enqueue(20)
     q.enqueue(30)
+
     expect(q.to_s).must_equal "[10, 20, 30]"
   end
 
@@ -50,7 +51,7 @@
     expect(q.empty?).must_equal true
   end
 
-  it "removes the right something (LIFO)" do
+  it "removes the right something (FIFO)" do
 
     q = Queue.new
     q.enqueue(5)
@@ -111,4 +112,33 @@
 
     expect(q.to_s).must_equal('[40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210]')
   end
+
+  it "calculates queues length/size" do
+    q = Queue.new
+    q.enqueue(1)
+    q.enqueue(1)
+    q.enqueue(1)
+    q.enqueue(1) 
+    q.enqueue(1)
+    q.enqueue(1)
+    q.enqueue(1)
+    q.enqueue(1) 
+    q.enqueue(1)
+    q.enqueue(1)
+    q.enqueue(1)
+    q.enqueue(1) 
+    q.enqueue(1)
+    q.enqueue(1)
+    q.enqueue(1)
+    q.enqueue(1)
+    q.enqueue(1)
+    q.enqueue(1)
+    q.enqueue(1)
+    q.enqueue(1)
+    q.dequeue
+    q.dequeue
+    q.dequeue
+    q.dequeue
+    expect(q.size).must_equal(16)
+  end
 end