Concept of Doubly Ended Queue
Doubly Ended Queue (Deque): A deque is a data structure that allows insertion and deletion of elements from both ends (front and rear). It is a generalized form of a queue.
Deques are widely used in scenarios where elements need to be accessed or modified from both ends efficiently.
Types of Deques:
Operations on Deque:
- Insert at front: Add an element to the front of the deque.
- Insert at rear: Add an element to the rear of the deque.
- Delete from front: Remove an element from the front of the deque.
- Delete from rear: Remove an element from the rear of the deque.
- Peek front: Access the front element without removing it.
- Peek rear: Access the rear element without removing it.
Applications:
- Implementing sliding window problems.
- Palindrome checking.
- Job scheduling and task management.
Advantages:
- Flexible operations from both ends.
- Efficient for certain algorithms and use cases.
Disadvantages:
- Requires more memory compared to a simple queue.
- Implementation can be complex for certain operations.
Time Complexity:
- Insertion and deletion at both ends: O(1).
- Accessing elements: O(n) in a linear deque.