Key Difference Between Linked list and Array
Let’s look at the key difference between linked list and Array, which will help us get better understanding which of them we should use.
| Aspect | Linked List | Array |
|---|---|---|
| Memory Allocation | Dynamic memory allocation, each node is allocated separately, allowing for flexible memory usage | Static memory allocation, all elements are allocated in contiguous memory locations |
| Access Time | Access time is O(n), as you need to traverse the list from the head to reach a specific element | Access time is O(1) for accessing elements by index |
| Insertion/Deletion Time | O(1) for insertion/deletion at the beginning or end of the list, O(n) for insertion/deletion in the middle | O(n) for insertion/deletion in the middle (shifting elements), O(1) for insertion/deletion at the end |
| Memory Overhead | Additional memory overhead for storing pointers/references to the next node | Minimal memory overhead, as elements are stored in contiguous memory locations |
| Dynamic Resizing | No need for resizing, as memory allocation is dynamic | May require resizing (reallocating memory) when the array reaches capacity, which can be an expensive operation |
| Cache Friendliness | Poor cache locality due to scattered memory access, impacting performance | Good cache locality due to contiguous memory allocation, leading to better performance |
| Usage | Suitable for applications requiring frequent insertion/deletion or where memory usage is unpredictable | Suitable for applications requiring fast random access or when memory usage is known upfront |
| Implementation | More complex implementation due to the need for handling pointers/references | Relatively simpler implementation |
| Examples | Singly linked list, doubly linked list, circular linked list | Static arrays, dynamic arrays (e.g., std::vector in C++), matrices |
Which is better linked list or array?
Linked lists and arrays have their own strengths and weaknesses. The choice between them depends on the specific requirements of the task at hand. Arrays are better when you need fast access to elements, while linked lists are better when you need to perform frequent insertions and deletions.