Python-Data-Structures-and-Algorithms

Stack class

This is a Python class that implements a stack data structure. A stack is a linear data structure in which elements are added and removed from one end, called the top. The stack follows the last-in, first-out (LIFO) principle, which means that the last element added to the stack is the first element to be removed.

The Stack class has the following methods:

• __init__(self): Initializes the stack.
• is_empty(self): Returns True if the stack is empty, False otherwise.
• push(self, item): Adds an item to the stack.
• pop(self): Removes an item from the stack and returns it.
• peek(self): Returns the top item on the stack without removing it.
• size(self): Returns the number of items in the stack.
• __str__(self): Returns a string representation of the stack.

Here is an example of how to use the Stack class: python

s = Stack() print(s) [] print(s.is_empty()) True s.push(1) s.push(2) s.push(3) print(s) [1, 2, 3] print(s.pop()) 3 print(s.peek()) 2 print(s.size()) 2 The Stack class is a useful data structure for implementing a variety of algorithms, such as the infix-to-postfix conversion algorithm and the binary search algorithm. You can view code here [stack class](/Starting Files/a_star.py)