diff --git a/stacks_queues/queue.py b/stacks_queues/queue.py index d66dab2..a61184b 100644 --- a/stacks_queues/queue.py +++ b/stacks_queues/queue.py @@ -15,7 +15,7 @@ def __init__(self): self.front = -1 self.rear = -1 self.size = 0 - + def enqueue(self, element): """ Adds an element to the Queue @@ -23,34 +23,59 @@ def enqueue(self, element): In the store are occupied returns None """ - pass + if self.size == 0: + self.front = 0 + + elif self.size == self.buffer_size: + raise QueueFullException("Error message") + + self.rear = (self.rear + 1) % self.buffer_size + self.store[self.rear] = element + self.size += 1 + return None def dequeue(self): """ Removes and returns an element from the Queue Raises a QueueEmptyException if The Queue is empty. """ - pass + try: + temp = self.store[self.front] + self.store[self.front] = None + self.front = (self.front + 1) % self.buffer_size + self.size -= 1 + return temp + except: + raise QueueEmptyException("Error message") def front(self): """ Returns an element from the front of the Queue and None if the Queue is empty. Does not remove anything. """ - pass - + try: + return self.store[self.front] + except: + raise QueueEmptyException("Error message") def size(self): """ Returns the number of elements in The Queue """ - pass + try: + return self.size + except: + raise QueueEmptyException("Error message") + def empty(self): """ Returns True if the Queue is empty And False otherwise. """ - pass + try: + return self.size == 0 + except: + raise QueueEmptyException("Error message") def __str__(self): """ Returns the Queue in String form like: @@ -58,4 +83,18 @@ def __str__(self): Starting with the front of the Queue and ending with the rear of the Queue. """ - pass + nodes = [] + back = self.rear + + if self.size == 0: + return nodes + + current = self.front + + while current != back: + nodes.append(self.store[current]) + current = (current + 1) % self.buffer_size + + nodes.append(self.store[back]) + + return str(nodes) diff --git a/stacks_queues/stack.py b/stacks_queues/stack.py index 94fb2a6..a7ee3c1 100644 --- a/stacks_queues/stack.py +++ b/stacks_queues/stack.py @@ -12,7 +12,8 @@ def push(self, element): """ Adds an element to the top of the Stack. Returns None """ - pass + self.store.add_last(element) + return None def pop(self): """ Removes an element from the top @@ -21,13 +22,20 @@ def pop(self): The Stack is empty. returns None """ - pass + try: + return self.store.remove_last() + except: + raise StackEmptyException + def empty(self): """ Returns True if the Stack is empty And False otherwise """ - pass + if self.store.length() == 0: + return True + + return False def __str__(self): """ Returns the Stack in String form like: @@ -35,4 +43,4 @@ def __str__(self): Starting with the top of the Stack and ending with the bottom of the Stack. """ - pass + return self.store.visit()