diff --git a/stacks_queues/queue.py b/stacks_queues/queue.py index d66dab2..0c85fe9 100644 --- a/stacks_queues/queue.py +++ b/stacks_queues/queue.py @@ -1,4 +1,3 @@ - INITIAL_QUEUE_SIZE = 20 class QueueFullException(Exception): @@ -15,7 +14,7 @@ def __init__(self): self.front = -1 self.rear = -1 self.size = 0 - + def enqueue(self, element): """ Adds an element to the Queue @@ -23,34 +22,53 @@ def enqueue(self, element): In the store are occupied returns None """ - pass + if self.front == -1: + self.front = 0 + self.rear = 0 + elif self.rear == self.front: + raise QueueFullException("Queue is full!") + self.store[self.rear] = element + self.rear = (self.rear + 1) % self.buffer_size + 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.size == 0: + raise QueueEmptyException('Queue is empty') + + element = self.store[self.front] + self.store[self.front] = None + self.front = (self.front + 1) % self.buffer_size + if self.front == self.rear: + self.front = -1 + self.rear = -1 + self.size -= 1 + return element + def front(self): """ Returns an element from the front of the Queue and None if the Queue is empty. Does not remove anything. """ - pass + 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: @@ -58,4 +76,12 @@ def __str__(self): Starting with the front of the Queue and ending with the rear of the Queue. """ - pass + result = "" + num = 0 + curr = self.front + while num < self.size: + result += str(self.store[curr]) + ", " + curr = (curr + 1) % self.buffer_size + num += 1 + + return "[" + result[:-2] + "]" \ No newline at end of file diff --git a/stacks_queues/stack.py b/stacks_queues/stack.py index 94fb2a6..7c147e0 100644 --- a/stacks_queues/stack.py +++ b/stacks_queues/stack.py @@ -12,7 +12,7 @@ def push(self, element): """ Adds an element to the top of the Stack. Returns None """ - pass + return self.store.add_first(element) def pop(self): """ Removes an element from the top @@ -21,13 +21,13 @@ 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.empty() def __str__(self): """ Returns the Stack in String form like: @@ -35,4 +35,4 @@ def __str__(self): Starting with the top of the Stack and ending with the bottom of the Stack. """ - pass + return str(self.store)