C15 Alison McGinley Stacks & Queues

stacks_queues/queue.py

@@ -23,39 +23,71 @@ def enqueue(self, element):
             In the store are occupied
             returns None
         """
-        pass
+        if self.size == self.buffer_size:
+            raise QueueFullException('Queue is full')
+
+        if self.front == -1:
+            self.front = 0
+
+        self.rear = (self.rear + 1) % self.buffer_size
+        self.size += 1
+
+        self.store[self.rear] = element
+
 
     def dequeue(self):
         """ Removes and returns an element from the Queue
             Raises a QueueEmptyException if 
             The Queue is empty.
         """
-        pass
+        if self.size == 0:
+            raise QueueEmptyException('Queue is empty')
+        if self.size == 1:
+            self.rear = -1
+
+        value = self.store[self.front]
+        self.store[self.front] = None
+
+        self.front = self.front + 1 % self.buffer_size
+
+        self.size -= 1
+
+        return value
+
 
     def front(self):
         """ Returns an element from the front
             of the Queue and None if the Queue
             is empty.  Does not remove anything.
         """
-        pass
+        if self.size == 0:
+            return QueueEmptyException('Queue is empty')
+
+        return self.front
 
 
     def size(self):
         """ Returns the number of elements in
             The Queue
         """
-        pass
+        return self.size
 
     def empty(self):
         """ Returns True if the Queue is empty
             And False otherwise.
         """
-        pass
+        return True if self.size == 0 else False
 
     def __str__(self):
         """ Returns the Queue in String form like:
             [3, 4, 7]
             Starting with the front of the Queue and
             ending with the rear of the Queue.
         """
-        pass
+        values = []
+
+        for i in range(self.front, self.front+self.size):
+            i %= self.buffer_size
+            values.append(self.store[i])
+
+        return str(values)

stacks_queues/stack.py

@@ -12,7 +12,7 @@ def push(self, element):
         """ Adds an element to the top of the Stack.
             Returns None
         """
-        pass
+        self.store.add_first(element)
 
     def pop(self):
         """ Removes an element from the top
@@ -21,18 +21,21 @@ def pop(self):
             The Stack is empty.
             returns None
         """
-        pass
+        if self.store.length() == 0:
+            raise StackEmptyException('Stack is empty')
+
+        return self.store.remove_first()
 
     def empty(self):
         """ Returns True if the Stack is empty
             And False otherwise
         """
-        pass
+        return True if self.store.length() == 0 else False
 
     def __str__(self):
         """ Returns the Stack in String form like:
             [3, 4, 7]
             Starting with the top of the Stack and
             ending with the bottom of the Stack.
         """
-        pass
+        return self.store.__str__()