How do you choose between a linked list and an array?

Choosing between a linked list and an array depends on the specific requirements of your data structure, such as insertion, deletion, and access needs.

A linked list and an array are both fundamental data structures in computer science, but they have different strengths and weaknesses. The choice between the two often depends on the specific needs of your program.

If you need to frequently access elements by their index, an array is the better choice. Arrays allow for constant-time access to any element, meaning it takes the same amount of time to access an element regardless of its position in the array. This is because arrays are contiguous blocks of memory, so the address of any element can be calculated if the base address and the size of an element are known.

On the other hand, if your program requires frequent insertions and deletions, a linked list may be more suitable. In a linked list, elements are not stored contiguously but are linked together using pointers. This means that insertions and deletions only require changing a few pointers, which can be done in constant time. However, accessing an element in a linked list requires traversing the list from the start until the desired element is found, which takes linear time.

Another factor to consider is memory usage. Arrays require a block of memory large enough to hold all elements at the time of creation, and resizing an array can be costly in terms of time and resources. In contrast, linked lists can grow and shrink dynamically, using exactly as much memory as they need at any given time.

In summary, if your program requires fast access to elements by index, an array is the better choice. If your program requires frequent insertions and deletions, a linked list is more suitable. And if memory usage is a concern, a linked list may be the better option due to its dynamic size.