🚀 Kotlin Algorithms Practice – HackerRank 30 Days of Code Challenge

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📑 Table of Contents

• 🚀 Project Overview
• 🎯 Project Goals
• 🛠 Tech Stack
• 📂 Project Structure
• 📚 Topics Covered
• 📅 Progress
• ▶️ Running the Code
• 🧠 Learning Notes
• 🌍 Why this Project Matters
• 👩🏻‍💻 About the Developer
• 🔗 Connect with Me

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🚀 Project Overview

This repository contains my solutions for the HackerRank 30 Days of Code Challenge, implemented using Kotlin.

The goal of this challenge is to strengthen:

• Algorithmic Thinking
• Problem-solving Skills
• Core Programming Fundamentals

Each day introduces a new programming concept and coding challenge.

📚 Official Challenge https://www.hackerrank.com/domains/tutorials/30-days-of-code

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🎯 Project Goals

This project was created to:

• Improve algorithmic thinking
• Strengthen core programming fundamentals
• Practice clean and readable Kotlin code
• Maintain daily coding discipline
• Prepare for technical interviews in global tech companies

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🛠 Tech Stack

• Kotlin
• Algorithms & Data Structures
• Problem Solving
• HackerRank coding platform
• Git & GitHub

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📂 Project Structure

30DaysCode
│
├── Day0-Hello-World
│   └── Main.kt
│
├── Day01-Data-Types
│   └── Main.kt
│
├── Day02-Operators
│   └── Main.kt
│
├── Day03-Conditional-Statements
│   └── Main.kt
│
├── Day04-Class-Instance
│   └── Main.kt
│
├── Day05-Loops
│   └── Main.kt
│
├── Day06-Review
│   └── Main.kt
│
├── Day07-Arrays
│   └── Main.kt
│
├── Day08-Dictionaries-Maps
│   └── Main.kt
│
├── Day09-Recursion
│   └── Main.kt
│
├── Day10-Binary-Numbers
│   └── Main.kt
│
├── Day11-2D-Arrays
│   └── Main.kt
│
├── Day12-Inheritance
│   └── Main.kt
│
├── Day13-Abstract-Classes
│   └── Main.kt
│
├── Day14-Scope
│   └── Main.kt
│
├── Day15-Linked-List
│   └── Main.kt
│
├── Day16-Exceptions-String-Integer
│   └── Main.kt
│
├── Day17-Exceptions
│   └── Main.kt
│
├── Day18-Queues-Stacks
│   └── Main.kt
│
├── Day19-Interfaces
│   └── Main.kt
│
├── Day20-Sorting
│   └── Main.kt
│
├── Day21-Generics
│   └── Main.kt
│
├── Day22-Binary-Search-Trees
│   └── Main.kt
│
├── Day23-BST-Level-Order-Traversal
│   └── Main.kt
│
├── Day24-Linked-Lists
│   └── Main.kt
│
├── Day25-Running-Time-Complexity
│   └── Main.kt
│
├── Day26-Nested-Logic
│   └── Main.kt
│
├── Day27-Testing
│   └── Main.kt
│
├── Day28-RegEx-Patterns-Databases
│   └── Main.kt
│
└── Day29-Bitwise
    └── Main.kt

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📚 Topics Covered

During the challenge, the following programming concepts are explored:

• Data types
• Conditional logic
• Loops
• Functions
• Arrays
• Dictionaries / Maps
• Recursion
• Object-Oriented Programming
• Algorithmic thinking
• Debugging and code optimization

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📅 Progress

Day	Topic	Status
Day 0	Hello World	✅
Day 1	Data Types	✅
Day 2	Operators	✅
Day 3	Conditional Statements	✅
Day 4	Class vs Instance	✅
Day 5	Loops	✅
Day 6	Review	✅
Day 7	Arrays	✅
Day 8	Dictionaries & Maps	⏳
Day 9	Recursion	⏳
Day 10	Binary Numbers	⏳
Day 11	2D Arrays	⏳
Day 12	Inheritance	⏳
Day 13	Abstract Classes	⏳
Day 14	Scope	⏳
Day 15	Linked List	⏳
Day 16	Exceptions - String to Integer	⏳
Day 17	More Exceptions	⏳
Day 18	Queues and Stacks	⏳
Day 19	Interfaces	⏳
Day 20	Sorting	⏳
Day 21	Generics	⏳
Day 22	Binary Search Trees	⏳
Day 23	BST Level-Order Traversal	⏳
Day 24	More Linked Lists	⏳
Day 25	Running Time and Complexity	⏳
Day 26	Nested Logic	⏳
Day 27	Testing	⏳
Day 28	RegEx, Patterns, and Intro to Databases	⏳
Day 29	Bitwise AND	⏳
Day 30	Advanced Challenges	⏳

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▶️ Running the Code

Click to expand instructions

1️⃣ Clone the repository

git clone https://github.com/Laura-Oliveira/30DaysCode.git

2️⃣ Navigate to the project

cd 30DaysCode

3️⃣ Compile the Kotlin code

kotlinc Main.kt -include-runtime -d program.jar

4️⃣ Run the Program

java -jar program.jar

You can also run the solutions using:

• IntelliJ IDEA [https://www.jetbrains.com/idea/]
• Android Studio [https://developer.android.com/studio]

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🧠 Learning Notes

During this challenge I aim to improve: • Algorithmic thinking • Kotlin problem-solving patterns • Time complexity awareness • Writing clean and readable code

Each solution focuses not only on solving the problem, but also on keeping the implementation clear, maintainable, and idiomatic in Kotlin.

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🌍 Why this Project Matters

Consistent algorithm practice is essential for developers who want to:

• Build high-quality software
• Improve logical reasoning
• Succeed in technical interviews

This repository demonstrates:

• 📈 Continuous learning mindset
• 🧠 Problem-solving and algorithmic thinking
• ✏️ Clean and readable Kotlin code
• 🛠 Practical programming discipline

These are key qualities valued by engineering teams and hiring managers worldwide, especially in product-driven tech companies.

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👩🏻‍💻 About the Developer

Laura Oliveira
Android Engineer | Kotlin Developer

I build modern Android applications using Kotlin/Java, focusing on clean architecture, scalability, and high-quality code.

🔧 Core Skills

• Kotlin
• Java
• Android SDK
• MVVM Architecture
• Coroutines & Concurrency
• Firebase
• REST APIs

🌍 Open to international opportunities

Remote • Hybrid • Relocation

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🔗 Connect with Me

💼 LinkedIn: https://www.linkedin.com/in/laura-oliveira-mobile/

🌐 Portfolio: https://laura-oliveira.github.io/

📧 Email: laura.oliveira.tech@gmail.com

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⭐ If you find this project helpful, consider giving it a star!

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#30DaysOfCode #Kotlin #Algorithms #ProblemSolving #SoftwareEngineering