Coding Challenges

Solutions and tests for coding problems from platforms like LeetCode, HackerRank, and seasonal events like Advent of Code. This repository is organized as a .NET solution with projects per source/platform and is designed to be built and validated via automated tests.

Purpose

This repo aims to:

• Document solutions to algorithmic challenges over time.
• Practice clean, test-driven problem solving in C#/.NET.
• Provide a browsable reference of techniques, patterns, and trade-offs.
• Encourage learning and collaboration through readable code and tests.

Projects in this Solution

The Visual Studio solution (Coding-Challenges.sln) currently includes the following projects:

• tests/LeetCode.Tests — Unit tests (and often the implementations) for LeetCode problems.
• tests/HackerRank.Tests — Unit tests (and often the implementations) for HackerRank challenges.
• tests/AdventOfCode.Tests — Unit tests and inputs for Advent of Code (multiple years/days).

Note: Implementations for problems may live alongside their tests within these projects. For Advent of Code, you will also find input files and per-day structures under tests/AdventOfCode.Tests.

Repository Layout

• Coding-Challenges.sln — Solution file referencing all projects and solution items.
• tests/ — All test projects, each grouping problems by platform or event.
  • LeetCode.Tests/
  • HackerRank.Tests/
  • AdventOfCode.Tests/ (contains many problems, inputs, and helpers)
• README.md, LICENSE, .gitignore
• global.json — Pins the .NET SDK (see below)

Prerequisites

• .NET SDK 9.0 (see global.json for the pinned version).
  • Install from the official .NET download page.

Getting Started

1. Clone the repository

   git clone <this-repo-url>
   cd coding-challenges

2. Build the solution

   dotnet build

3. Run all tests

   dotnet test

Run tests for a single project

dotnet test tests/LeetCode.Tests/LeetCode.Tests.csproj
dotnet test tests/HackerRank.Tests/HackerRank.Tests.csproj
dotnet test tests/AdventOfCode.Tests/AdventOfCode.Tests.csproj

Filter tests by name or trait

dotnet test --filter FullyQualifiedName~TwoSum
dotnet test tests/AdventOfCode.Tests/AdventOfCode.Tests.csproj --filter TestCategory=Day05

How to Navigate

• Browse the tests projects to find problems by platform/event.
• For Advent of Code, look for folders/files named by year and day; inputs are usually included under the same project tree.
• Many problems include both the solution and its tests side by side to keep each task self-contained.

Contributing / Adding New Solutions

• Prefer adding new problems within the corresponding tests/* project to keep implementations co-located with tests.
• Follow consistent naming (problem name or AoC year/day) and include a clear, minimal set of tests for correctness and edge cases.
• If you introduce shared helpers, keep them small and well-named; avoid over-abstracting.
• Open a PR with a brief explanation of the approach and any complexity notes.

License

See LICENSE for details.

Disclaimer

These solutions are intended for learning. Do not submit code verbatim to competitive platforms where it violates terms. Use this repository to understand approaches and verify your own solutions.

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Happy Coding! 🚀