MD ARIFUL HAQUE

Posted on Oct 23

🌟 Hacktoberfest 2025 Contribution Chronicles: Solving LeetCode in PHP

#devchallenge #hacktoberfest #opensource

Hacktoberfest: Contribution Chronicles

This is a submission for the 2025 Hacktoberfest Writing Challenge: Contribution Chronicles

Repository: mah-shamim/leet-code-in-php

💡 The Idea Behind the Project

As a PHP developer, I’ve often noticed that while most algorithmic problems are solved using Python, Java, or C++, there’s limited learning material for developers who want to master data structures and algorithms using PHP — especially legacy versions like PHP, which are still used in production by many companies.

That inspired me to create this repository:
👉 LeetCode in PHP — a collection of optimized PHP solutions to classic LeetCode problems, explained in detail and documented like a tutorial.

It’s not just about solving problems — it’s about making algorithms accessible to PHP developers who want to strengthen their fundamentals without switching languages.

🔧 What I Worked On

During Hacktoberfest 2025, I focused on:

Structuring the repository for easy navigation (by problem type and difficulty).
Adding step-by-step explanations for each problem.
Ensuring compatibility with PHP and CLI execution.
Improving code readability with clear comments and time complexity notes.
Writing clean, testable functions with no external dependencies.

Here’s a quick look at one of the problems I contributed — “Letter Combinations of a Phone Number.”

🧩 Example: Letter Combinations of a Phone Number

Problem:
Given a string containing digits from 2-9, return all possible letter combinations that the number could represent.

Solution (PHP):

<?php
function letterCombinations($digits) {
    if (empty($digits)) return [];
    $map = [
        '2' => ['a','b','c'],
        '3' => ['d','e','f'],
        '4' => ['g','h','i'],
        '5' => ['j','k','l'],
        '6' => ['m','n','o'],
        '7' => ['p','q','r','s'],
        '8' => ['t','u','v'],
        '9' => ['w','x','y','z']
    ];
    $result = [''];
    foreach (str_split($digits) as $digit) {
        $temp = [];
        foreach ($result as $combination) {
            foreach ($map[$digit] as $char) {
                $temp[] = $combination . $char;
            }
        }
        $result = $temp;
    }
    return $result;
}

// Example
print_r(letterCombinations("23"));

Output:

Array
(
    [0] => ad
    [1] => ae
    [2] => af
    [3] => bd
    [4] => be
    [5] => bf
    [6] => cd
    [7] => ce
    [8] => cf
)

🚀 What I’m Proud Of

✅ Making algorithmic problem-solving approachable for PHP developers.
✅ Using legacy PHP to prove that logic, not language, defines efficiency.
✅ Writing tutorial-style explanations for every contributor or learner to follow easily.
✅ Encouraging contributions from others to solve new problems or optimize existing ones.

🧠 What I Learned

How to refactor recursive and backtracking algorithms for PHP’s older runtime.
The importance of code readability and documentation in open source.
How community contributions can improve both code quality and motivation.
That open-source collaboration is less about competition, and more about collective learning.

🧭 Challenges I Overcame

Balancing backward compatibility with performance optimization.
Refactoring modern PHP features (like generators or anonymous functions) into PHP equivalents.
Managing array-based recursion without built-in advanced helpers.
Writing problems in a consistent structure: Problem → Approach → Code → Complexity → Example Output.

🤝 How to Contribute

You can help make this repository even better!
🔹 Fork the repo
🔹 Solve a new LeetCode problem in PHP
🔹 Follow the naming and documentation format
🔹 Submit a pull request 🚀

📍 Repo: github.com/mah-shamim/leet-code-in-php

🎉 Final Thoughts

Hacktoberfest 2025 reminded me that sharing knowledge is as valuable as writing code.
Through this project, I hope to inspire more PHP developers to dive into algorithms, contribute confidently to open source, and keep learning — no matter what version of PHP they use!

“Code is temporary, learning is permanent.” 💻

Tags: #hacktoberfest #php #opensource #leetcode #programming #tutorial

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