What are the differences between using arrays and linked lists in the implementation of data structures?

Arrays and linked lists are two fundamental data structures that differ in how they store and organize elements.

Arrays:

• Elements are stored in a contiguous block of memory.
• Fast access by index (O(1)).
• Inserting and deleting elements in the middle of an array are costly operations (O(n)) because elements need to be shifted.
• The size of the array is fixed or requires reallocation when resizing.

Linked lists:

• Elements (nodes) are stored in different memory locations, each containing a reference to the next (and/or previous) element.
• Access by index requires sequential traversal (O(n)).
• Inserting and deleting elements anywhere in the list is fast (O(1)) if there is a reference to the node.
• The size is dynamic, easily expandable without reallocation.