feature: review README (#34)

Update README file

Author: onixlas

README.md

@@ -1,37 +1,71 @@
-# LeetCode 75 Solutions
+# Algorithmic Patterns
 
-This repository contains my solutions to the problems from the 
-[LeetCode 75 Study Plan](https://leetcode.com/studyplan/leetcode-75/). The study plan covers essential algorithmic 
-topics and is a great way to improve coding interview skills.
+This repository contains curated solutions to a subset of common algorithmic problems, primarily based on the LeetCode 75 study plan.
 
-## 📌 About LeetCode 75
+The purpose of this repository is **to maintain algorithmic fluency and document common problem-solving patterns** that frequently appear in technical interviews and real-world engineering tasks.
 
-The LeetCode 75 Study Plan is a curated list of 75 problems covering:
-- Array & String manipulation
-- Two Pointers
-- Sliding Window
-- Prefix Sum
-- Hash Map/Set
-- Stack
-- Queue
-- And other important DSA concepts
+This is not intended as a competitive programming showcase, but rather as a structured reference for fundamental data structures and algorithms.
+
+---
+
+## 📌 Scope
+
+The problems cover a range of foundational algorithmic topics, including:
+- Arrays and strings
+- Two pointers
+- Sliding window
+- Prefix sums
+- Hash-based data structures
+- Stack and queue
+- Basic graph and traversal patterns
+
+Each solution focuses on:
+- clarity and readability
+- explicit time and space complexity
+- well-known algorithmic patterns rather than clever tricks
+
+---
 
 ## 🗂 Repository Structure
 
 ```
-leetcode75/
-├── array-string/ # Array & String problems
-├── two-pointers/ # Two Pointers problems
-├── sliding-window/ # Sliding Window problems
-├── prefix-sum/ # Prefix Sum problems
-└── ... # Other categories
+.
+├── pyproject.toml        # Project configuration
+├── src/
+│   ├── array_string/     # Array and string manipulation patterns
+│   ├── hashmap_set/      # Hash map and set based problems
+│   ├── prefix_sum/       # Prefix sum techniques
+│   ├── sliding_window/   # Sliding window pattern
+│   ├── two_pointers/     # Two pointers pattern
+│   ├── stack/            # Stack-based problems
+│   └── queue/            # Queue-based problems
+│
+│   # Each submodule follows a consistent structure:
+│   # <problem_name>/
+│   # ├── __init__.py
+│   # └── solution.py
+│
+└── tests/                # Tests for all problems
 ```
 
-## 🚀 How to Use
+---
+
+## 🧠 Design principles
+
+- Clean, readable Python code
+- Emphasis on algorithmic patterns
+- Avoidance of overly compact or non-obvious solutions
+- Explicit handling of edge cases
+
+---
+
+## 🛠 Language
+
+- Python
+
+---
+
+## 🔎 Notes
+
+This repository complements my primary work in **machine learning and LLM-based systems**, where a solid understanding of algorithms and data structures remains essential for building reliable and scalable production systems.
 
-1. Clone the repository:
-   ```bash
-   git clone https://github.com/onixlas/leetcode75.git
-   ```
-2. Navigate to the specific problem category and solution file.
-3. Solutions are written in Python