# 18. Reverse a Doubly Linked List

The problem can be found at the following link: [Question Link](https://www.geeksforgeeks.org/problems/reverse-a-doubly-linked-list/1)

![](https://badgen.net/badge/Level/Basic/green)

## My Approach

To reverse a doubly linked list, I go through the list, swapping the `prev` and `next` pointers for each node while updating the head during each iteration.

## Time and Auxiliary Space Complexity

* **Time Complexity**: `O(N)`, where `N` is the number of nodes in the doubly linked list.
* **Auxiliary Space Complexity**: `O(1)`, as the reversal is done in-place without using additional space.

## Code (C++)

```cpp
class Solution {
public:
    Node* reverseDLL(Node* head) {
        Node* curr = head;

        while (curr) {
            head = curr;
            Node* prev = curr->prev;
            curr->prev = curr->next;
            curr->next = prev;
            curr = curr->prev;
        }

        return head;
    }
};
```

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