Create solution_java.java

[arya2004]

📝 Issue Reference:

Fixes issue: #8

🔍 Checklist:

Please ensure the following before submitting your PR:

• I have placed my solution in the correct folder (solutions/dayXX/).
• My code follows clean coding practices and is efficient.
• I have added comments in my code to explain the approach.
• I have updated the README.md for the specific day with a brief explanation of my solution.
• I have tested the solution on LeetCode and it works correctly.

🔧 Solution Details:

• Language Used: Java
• Time Complexity: O(n)
• Space Complexity: O(n)