Highest Value Palindrome 🌟

Introduction

This Python program calculates the highest value palindrome that can be obtained by changing at most k characters in a given string s. A palindrome is a string that reads the same forwards and backward. This program ensures that the resulting palindrome has the maximum possible numerical value.

Why This Exercise? 💡

I selected this exercise because it presents an intriguing challenge: transforming a string into a palindrome while maximizing its numerical value. This problem has real-world applications in data validation, error correction, and even game design. By solving this problem, I aimed to enhance my skills in string manipulation and algorithmic thinking.

How to Run 🚀

To run the "Highest Value Palindrome" program, follow these simple steps:

1. Prerequisites:

   • Ensure you have Python 3.x installed on your system.

2. Clone the Repository:

   • Clone this repository to your local machine using your preferred method.

3. Navigate to the Project Directory:

   • Open a terminal or command prompt in the project directory.

4. Run the Program:

   • Execute the following command to start the program:

     python3 palindrome.py

5. Input:

   • Follow the on-screen prompts to input the string, its length, and the maximum number of allowed changes.

6. Output:

   • The program will calculate and display the highest value palindrome based on your inputs.

Example Usage 📝

Here are some example usages of the program:

1. Input string: "1231", Length: 4, Changes allowed: 3

   • Output: "9339"

2. Input string: "12321", Length: 5, Changes allowed: 1

   • Output: "12921"

3. Input string: "12345", Length: 5, Changes allowed: 2

   • Output: "54345"

4. Input string: "12345", Length: 5, Changes allowed: 4

   • Output: "99399"

5. Input string: "12345", Length: 5, Changes allowed: 5

   • Output: "99999"

Input Validation ✅

The program includes input validation to ensure that:

• The length n of the string is at least 1.
• The maximum number of changes allowed k is non-negative.

Here's an example of input validation in action:

Please enter a string representation of an integer (e.g., '12345'): 1
Please enter the length of the string (1 or greater): 1
Please enter the maximum number of changes allowed (0 or greater): -2

Highest Value Palindrome: Invalid input: n should be at least 1, and k should be non-negative.

Running Tests
Tests Completed

The program will reject invalid input and provide an informative error message.

Authors

• Obed Rayo