Stack and Queue

Stack

Last-In-First-Out

Main: push(), pop()

Auxiliary: top(), size(), empty()

Array-based Stack is most simple and fastest way.

Limit: Stack size must be defined before

Queue

First-In-First-Out

Main: enqueue(), dequeue()

Auxiliary: front(), size(), emty()

Array-based Queue is little tricky. 

deque: double ended. (front ------ rear)

Main: push_front(), push_back(), pop_front(), pop_back()

Auxiliary: size(), empty(), front(), back()

Doubly linked list based deque have O(1) functions

Quiz1: Where can we apply stack?

Quiz2: Where can we apply queue?