Add palindrome number checker with user input

[YASWANTH1976]

Adds a simple Python implementation to check whether a number is a palindrome using user input.
Includes basic input handling and examples.

Describe your change:

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request.
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
• If this pull request resolves one or more open issues then the description above includes the issue number(s) with a closing keyword: "Fixes #ISSUE-NUMBER".

[himudigonda]

The string slicing (str(n)[::-1]) method is idiomatic Python but inefficient. I suggest a mathematical approach using modular arithmetic to achieve $O(1)$ space complexity.

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🔍 Analysis

Metric	Original (String-based)	Optimized (Mathematical)
Time Complexity	$O(n)$	$O(\log_{10} n)$
Space Complexity	$O(n)$ (Creates string copies)	$O(1)$ (No extra allocation)
Mathematical Correctness	Relies on string reversal	Handles digit logic natively

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🛠️ Refactored Implementation

def is_palindrome(number: int) -> bool:
    """
    Determines if an integer is a palindrome without string conversion.
    
    Logic:
    1. Filter out negative numbers and multiples of 10.
    2. Reverse the second half of the number.
    3. Compare the two halves.
    """
    # Negative numbers and numbers ending in 0 (except 0) are not palindromes
    if number < 0 or (number % 10 == 0 and number != 0):
        return False

    reversed_half = 0
    # Reverse only half of the digits to prevent overflow and save time
    while number > reversed_half:
        reversed_half = (reversed_half * 10) + (number % 10)
        number //= 10

    # For even digits: number == reversed_half
    # For odd digits: number == reversed_half // 10 (removes middle digit)
    return number == reversed_half or number == reversed_half // 10

[algorithms-keeper]

Click here to look at the relevant links ⬇️

🔗 Relevant Links

Repository:

• Contributing guidelines
• Project Euler solution guidelines

Python:

• Formatted string literals (f-strings)
• Type hints
• doctest
• unittest
• pytest

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[algorithms-keeper]

As there is no test file in this pull request nor any test function or class in the file maths/palindrome_number.py, please provide doctest for the function is_palindrome

[YASWANTH1976]

Added required doctests for is_palindrome as requested. Please review.