Paper - Malakhova K.

stacks_queues/queue.py

@@ -1,4 +1,3 @@
-
 INITIAL_QUEUE_SIZE = 20
 
 class QueueFullException(Exception):
@@ -15,47 +14,70 @@ 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:
+            #The Queue is full
+            raise QueueFullException("Queue is full")
+        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:
+            #queue is empty
+            raise QueueEmptyException("Queue is empty")
+        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
+        value_list = []
+        for i in range(self.front, self.front + self.size):
+            i = i % self.buffer_size
+            value_list.append(self.store[i])
+        return str(value_list)

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 +21,18 @@ def pop(self):
             The Stack is empty.
             returns None
         """
-        pass
+        return self.store.remove_first()
 
     def empty(self):
         """ Returns True if the Stack is empty
             And False otherwise
         """
-        pass
+        return self.store.length() == 0 
 
     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__()