Question

Many times, stack is implemented as a linked list, Is array representation not good enough, in array we can perform push pop easily, and linked list over array complicates the code, and has no advantage over array implementation.

Can you give any example where a linked list implementation is more beneficial, or we cant do without it.

Answer 1

I would say that many practical implementations of stacks are written using arrays. For example, the .NET Stack implementation uses an array as a backing store.

Arrays are typically more efficient because you can keep the stack nodes all nearby in contiguous memory that can fit nicely in your fast cache lines on the processor.

I imagine you see textbook implementations of stacks that use linked lists because they’re easier to write and don’t force you to write a little bit of extra code to manage the backing array store as well as come up with a growth/copy/reserve space heuristic.

In addition, if you’re really pressed to use little memory, a linked list implementation might make sense since you don’t “waste” space that’s not currently used. However, on modern processors with plenty of memory, it’s typically better to use arrays to gain the cache advantages they offer rather than worry about page faults with the linked list approach.