DSA Practice

Data structures and algorithms problems from HackerRank, solved in Java, Python, and (where noted) PHP. Each problem has its own folder with a written approach, complexity analysis, and difficulty rating.

Structure

Problems are organized by topic. Each problem folder contains:

• README.md — problem statement, approach explanation, time/space complexity, and difficulty
• Solution.java, solution.py, and (where applicable) Solution.php — working solutions

Problems

Arrays

Problem	Difficulty	Languages
A Very Big Sum	Easy	Java, Python
Birthday Cake Candles	Easy	Java, Python, PHP
Compare the Triplets	Easy	Java, Python
Diagonal Difference	Easy	Java, Python
Mini-Max Sum	Easy	Java, Python, PHP
Plus Minus	Easy	Java, Python
Simple Array Sum	Easy	Java, Python

Implementation

Problem	Difficulty	Languages
Apple and Orange	Easy	Java, Python, PHP
Grading Students	Easy	Java, Python, PHP
Number Line Jumps	Easy	Java, Python, PHP
Staircase	Easy	Java, Python

Strings

Problem	Difficulty	Languages
Camel Case	Easy	Java, Python
Time Conversion	Easy	Java, Python, PHP

Approach

Every solution folder documents:

• The problem statement and a link to the original HackerRank challenge
• The reasoning behind the chosen approach
• Time and space complexity
• Which languages the problem is solved in