🧠 Algo Challenges

Welcome to the Algo Challenges repository — a collection of hand-picked algorithmic coding problems inspired by real company interviews I've personally taken part in (Amazon, Bolt, and more).

This repo is built to simulate real technical interviews, promote focused problem-solving, and help you improve your data structures and algorithms skills through disciplined practice.

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📚 What's Inside

Challenges are organized by company name in folders like:

amazon/WatchScore
bolt/SomeOtherChallenge

Each challenge contains:

• 📄 README.md — problem description and sample cases
• 🧪 __tests__/ — unit tests written using Jest
• ✍️ solution/ — an official solution you can check after solving

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🎯 How to Approach Challenges Effectively

To make the most out of your practice, follow these principles — just like in a real interview:

1. Read the problem description carefully
   Pay attention to constraints, edge cases, and sample inputs/outputs.

2. Think first, code later
   Plan your approach and write your code fully before running any tests — just like a real submission.

3. Run tests only when ready
   Validate your logic using the provided Jest tests by running yarn test.

4. If tests fail, avoid peeking

   • Try to debug without reading the test cases.
   • Use console.log or walk through your code logically to find the issue.

5. Still stuck?

   • Then look at the failing test case(s).
   • You can compare with the official solution in the solution/ folder only after a solid personal attempt.

6. Add complexity analysis to your solution
   At the top of your solution file, add a quick comment like:

   // Time: O(n); Space: O(1)

   This helps build the habit of analyzing code performance.

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🚀 Getting Started

1. Clone the repository

git clone https://github.com/bohdan-konovalov/algo-challenges.git
cd algo-challenges

2. Install dependencies

yarn install

3. Run the tests

yarn test

Tests are written using Jest and scoped to individual challenges.

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🔇 About Minimal Test Output

To encourage debugging and mimic real interview conditions, test output is silenced by default. When running tests, you’ll only see a summary like this:

Test Suites: 1 failed, 3 total
Tests:       5 failed, 12 total
Snapshots:   0 total
Time:        0.664 s

This gives you space to think before relying on test details.

To view full test logs:

Open the jest.config.js file and comment out the following line:

reporters: ["<rootDir>/silentSummaryReporter.js"],

Then re-run your tests with:

yarn test

This will enable detailed output including test names, errors, and stack traces.

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🏗 Project Structure

algo-challenges/
├── amazon/
│   └── WatchScore/
│       ├── __tests__/
│       |   └── index.test.ts
│       └── solution/
│       |   └── index.solution.ts
│       ├── index.ts
│       ├── README.md
├── bolt/
│   └── SomeOtherChallenge/
├── .gitignore
├── jest.config.js
├── package.json
├── README.md
├── silentSummaryReporter.js
├── tsconfig.json
└── yarn.lock

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🤝 Contributing

Have a cool challenge from an interview or a fun idea?
PRs are welcome — just follow the folder structure and testing style.

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Happy hacking, and treat every challenge like it’s your final interview round 💪