⚡ DSA-Solutions-Java

My Journey to Master Algorithms & Data Structures

This repository isn't just code—it's a structured roadmap of my technical growth. From basic arrays to complex dynamic programming, I document every pattern I learn.

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📚 Learning Roadmap & Patterns

I focus on Patterns, not just problems. Here is what I am currently mastering:

Pattern	Logic / Intuition	Problems Solved
Two Pointers	Reducing $O(n^2)$ to $O(n)$ using two indices.	Two Sum, Valid Palindrome
Prefix Logic	Precomputing values for $O(1)$ range queries.	Reverse Prefix
Math & Logic	Handling overflows and number theory.	Reverse Integer, Palindrome Number

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⏱️ Complexity Cheat Sheet (Java)

Data Structure	Access	Search	Insertion	Deletion
Array	$O(1)$	$O(n)$	$O(n)$	$O(n)$
ArrayList	$O(1)$	$O(n)$	$O(1)$*	$O(n)$
HashMap	$N/A$	$O(1)$	$O(1)$	$O(1)$

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🛠️ How to Use This Repo

1. Browse by Folder: Check the Leetcode folder for specific problem types.
2. Review Complexity: Every solution includes a // Time & Space Complexity comment at the top.
3. Run Locally: ```bash javac Leetcode/twosum.java java Leetcode.twosum