Implementing a Stack using Arrays

In this article, we will learn how to implement a stack data structure using arrays.

Problem Statement: Implement a stack using an array with the following operations:

• Push: Add an element to the top of the stack.

• Pop: Remove the top element from the stack.

• Peek/Top: Get the top element of the stack without removing it.

• isEmpty: Check if the stack is empty.

Example:

Let us create a stack of size 3

Stack s(3);

// Push elements to the stack

s.push(10);

s.push(20);

s.push(30);

// Get the top element

s.top(); // Output: 30

// Pop the top element

s.pop(); // Output: 30

// Check if the stack is empty

s.isEmpty(); // Output: false

Solution:

To solve this problem, we will follow these steps:

Steps to Implement:

1.    Define the Stack Class:

o   Create a class Stack with an array, a variable for the maximum size of the stack, and a variable for the index of the top element.

2.    Initialize the Stack:

o   In the constructor, initialize the array, set the maximum size, and set the top index to -1.

3.    Implement Push Operation:

o   Check if the stack is full. If not, add the element to the top of the stack and increment the top index.

4.    Implement Pop Operation:

o   Check if the stack is empty. If not, remove the top element from the stack and decrement the top index.

5.    Implement Top Operation:

o   Return the top element of the stack.

6.    Implement isEmpty Operation:

o   Check if the top index is -1.