Dhariniguru/LEETcOdE- — reverse-engineered prompt

I want a simple Java practice repo that solves the LeetCode style problems already listed here. Please fill out each problem folder with a clean working Java solution for that specific question, like palindrome number, running sum, shuffle the array, search insert position, add digits, and the other ones in the repo.

Keep it beginner friendly and organized so I can use it to study. Each solution should be easy to read, with short comments explaining the idea and the important steps. If it makes sense, add a tiny example or a simple way to run and verify the answer for each one. Make sure the code is correct and not overly fancy.

The README is basically empty, so please also write a useful one that explains what this repo is, how the solutions are organized, and how to run the Java files. If you need to, look up the current problem statements online so the solutions match the actual questions.