How do I reverse a doubly linked list?

How do I reverse a doubly linked list?

To reverse a doubly linked list, you need to swap the next and previous pointers for each node.

Can you provide a code example for that?

Sure! Here's a simple Python example:

class Node:
    def __init__(self, data):
        self.data = data
        self.next = None
        self.prev = None


def reverse_doubly_linked_list(head):
    current = head
    temp = None
    while current:
        temp = current.prev
        current.prev = current.next
        current.next = temp
        current = current.prev
    if temp:
        head = temp.prev
    return head

What are the time and space complexities of this algorithm?

The time complexity is O(n) because you traverse the list once, and the space complexity is O(1) since you only use a few pointers.