Briyana Haywood-Rock

stacks_queues/linked_list.py

@@ -1,4 +1,3 @@
-
 class EmptyListError(Exception):
     pass
 
@@ -48,7 +47,7 @@ def remove_first(self):
 
 
     def empty(self):
-      return not self.head
+        return not self.head
 
     # method to find if the linked list contains a node with specified value
     # returns true if found, false otherwise

stacks_queues/queue.py

@@ -2,10 +2,10 @@
 INITIAL_QUEUE_SIZE = 20
 
 class QueueFullException(Exception):
-    pass
+    print("QueueFullException: Queue is full!")
 
 class QueueEmptyException(Exception):
-    pass
+    print("QueueEmptyException: Queue is empty!")
 
 class Queue:
 
@@ -15,47 +15,70 @@ def __init__(self):
         self.front = -1
         self.rear = -1
         self.size = 0
-      
+
 
     def enqueue(self, element):
         """ Adds an element to the Queue
             Raises a QueueFullException if all elements
             In the store are occupied
             returns None
         """
-        pass
+        if (self.rear + 1) % self.buffer_size == self.front:
+            raise QueueFullException()
+        elif self.front == -1:
+            self.front = 0
+            self.rear = 0
+            self.store[self.rear] = element
+            self.size += 1
+        else:
+            self.rear = (self.rear +1) % self.buffer_size
+            self.store[self.rear] = element
+            self.size += 1
 
     def dequeue(self):
         """ Removes and returns an element from the Queue
             Raises a QueueEmptyException if 
             The Queue is empty.
         """
-        pass
+        if self.front == -1:
+            raise QueueEmptyException()
+        data = self.store[self.front]
+        self.front = (self.front +1) % self.buffer_size
+        self.size -= 1
+
+        return data
 
     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.empty():
+            return None
+        return self.store[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 self.size == 0
 
     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
+        # return self.store.__str__()
+        values = []
+        for i in range(self.front, self.front + self.size):
+            i = i % self.buffer_size
+            values.append(self.store[i])
+        return str(values)

stacks_queues/stack.py

@@ -1,7 +1,7 @@
 from stacks_queues.linked_list import LinkedList
 
 class StackEmptyException(Exception):
-    pass
+    print("StackEmptyException: Stack is empty")
 
 class Stack:
 
@@ -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 +21,20 @@ def pop(self):
             The Stack is empty.
             returns None
         """
-        pass
+        if self.store.empty():
+            raise StackEmptyException()
+        return self.store.remove_first()
 
     def empty(self):
         """ Returns True if the Stack is empty
             And False otherwise
         """
-        pass
+        return self.store.empty
 
     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__()