When should you prefer ArrayDeque and when should you avoid it?

ArrayDeque is a resizable array implementation of the Deque interface. It is an excellent choice when you need a structure that allows for efficient insertions and deletions from both ends. However, it has its specific use cases where it excels and others where it may not be the best option.

When to Prefer ArrayDeque

• Performance: ArrayDeque provides O(1) time complexity for add and remove operations at both ends, making it preferable for applications needing frequent operations on both ends.
• Memory Efficiency: It is more memory-efficient compared to LinkedList as it uses less overhead because it does not require storing the pointers to the next and previous elements.
• Queue Implementation: If you need a queue and stack implementation, ArrayDeque can serve both purposes effectively.

When to Avoid ArrayDeque

• Thread Safety: ArrayDeque is not thread-safe. If multiple threads are accessing the deque concurrently, consider using other options like ConcurrentLinkedDeque.
• Fixed Size: If you need a fixed-size deque that shouldn't grow or shrink dynamically, you should use an Array with predefined length instead of using ArrayDeque.
• Frequent Iterations: If you are iterating frequently through the structure, performance may degrade due to resizing issues.