Swift Data Structure and Algorithms

Stack

A stack is a Last In First Out (LIFO) data structure. You can think of a LIFO structure resembling a stack of plates; the last plate added to the stack is the first one removed. A stack is similar to an array but provides a more limited, controlled method of access. Unlike an array, which provides random access to individual elements, a stack implements a restrictive interface that tightly controls how elements of a stack are accessed.

Stack data structure

A stack implements the following three methods:

• push() - Adds an element to the bottom of a stack
• pop() - Removes and returns an element from the top of a stack
• peek() - Returns the top element ...