Chapter 21, Problem 1SA

Explanation of Solution

Stack:

A stack is a linear data structure. It follows FILO (first in last out) or LIFO (last-in-first-out).

• The two main operations performed on a stack are,
  • Push() – Adds item to stack.
  • Pop() – Removes item from stack.
• The stack is the container used to store objects which are added and removed in last-in-first-out (LIFO) or first-in-last-out (FILO) fashion.
• The stack has only one end for adding and removing items.
  • So when the method “pop()” is called on a stack, it removes the item that is added recently on the stack.
  • The first added item can be removed last...