What are the basic operations of a deque?

What are the basic operations of a deque?

A deque, or double-ended queue, allows insertion and deletion of elements from both ends. The basic operations include:

1. addFirst(element): Adds an element to the front.
2. addLast(element): Adds an element to the back.
3. removeFirst(): Removes the front element.
4. removeLast(): Removes the back element.
5. peekFirst(): Retrieves the front element without removing it.
6. peekLast(): Retrieves the back element without removing it.

Can you give me an example of how to use these operations in Python?

Sure! Here's a simple example using Python's collections.deque:

from collections import deque

# Create a deque
my_deque = deque()

# Add elements
my_deque.append(1)  # addLast
my_deque.appendleft(2)  # addFirst

# Remove elements
my_deque.pop()  # removeLast
my_deque.popleft()  # removeFirst

# Peek elements
first = my_deque[0]  # peekFirst
last = my_deque[-1]  # peekLast

What are some real-world applications of deques?

Deques are used in various applications such as:

1. Implementing queues for breadth-first search algorithms.
2. Managing tasks in scheduling systems.
3. Undo functionality in text editors.
4. Buffer management in streaming data.