Stacks

Question 1

What type of data structure is a stack?

Answer 1

Its a LIFO, which means last in first out.

Question 2

What are the use cases for a stack?

Answer 2

1 - Managing function calls
2 - Undo / Re Do Functionalities
3 - Routing
4 - Used with other algorithms

Question 3

What are two ways to implement a stack?

Answer 3

Using a array or a singly linked list.

Question 4

Using an array, how would we implement a stack?

Answer 4

To implement a stack using arrays in JavaScript, you can use the push and pop methods.

Question 5

Why would we not use shift and unshift when when implementing a stack with an array?

Answer 5

These methods will result in worse Big O notation. This is because every time we add or remove from the beginning, we have to re-index everything.

Question 6

How would you implement a stack with a singly linked list?

Implement it.

Answer 6

Add and remove from the beginning of the list instead of the end.

Question 7

When should you use stacks?

Answer 7

When you need to do inserting and removal operations.

Question 8

When should you not use stacks?

Answer 8

When you need to do searching and accessing.

Question 9

What is the Big O of insertion and removal for stacks?

Answer 9

Both are O(1).