Learn Codeby Explaining Your Thinking

Master algorithm interviews through Socratic dialogue. Explain your logic, earn code snippets, and watch your understanding deepen with every conversation.

.
Two Sum
Easy

How would you approach finding two numbers that add up to the target?

I could use a hash map to store values I've seen...

Great intuition! What would you store as keys and values?

Code Unlocked
def two_sum(nums, target):
    seen = {}
    for i, num in enumerate(nums):
        complement = target - num
        if complement in seen:
            return [seen[complement], i]
        seen[num] = i
Type your explanation...
How It Works

Three Steps to Mastery

A guided conversation that transforms how you think about algorithms

01

Explain Your Approach

Start by describing how you'd solve the problem. No code yet—just your thought process in plain English.

02

Refine Through Dialogue

Our AI guides you with Socratic questions, helping you discover solutions yourself rather than just giving answers.

03

Earn Your Code

Once you've demonstrated understanding, receive working code you truly comprehend—not just memorized.

Features

Built for Deep Understanding

Every feature is designed to help you truly comprehend algorithms, not just memorize solutions

Learn by Teaching

The best way to learn is to explain. dot200 makes you articulate your thinking before showing you code.

Run Against Real Tests

Execute your code against actual test cases. See exactly where your logic succeeds or fails.

Your Language, Your Way

Python, JavaScript, Java, C++, Go, Swift. Learn in the language you interview in.

Track Your Growth

See your improvement over time. Track sessions, topics mastered, and streaks.

Write Code in Your Language

Choose from 6+ popular programming languages to practice in

Python
JavaScript
Java
C++
Go
Swift

Simple, Transparent Pricing

Start free, upgrade when you're ready to go all-in

Free

$0/month

Perfect for getting started

  • 5 sessions per month
  • 50 messages per day
  • All topics available
  • Community support
Most Popular

Pro

$9.99/month

For serious interview prep

  • Unlimited sessions
  • Unlimited messages
  • Priority AI responses
  • Progress analytics
  • Priority support

Launch Deal: 50% off your first 3 months with code LAUNCH50

Frequently Asked Questions

Everything you need to know about dot200

LeetCode shows you solutions. dot200 helps you discover them yourself through guided conversation. Our Socratic method ensures you truly understand the logic, not just memorize patterns.

We currently support Python, JavaScript, Java, C++, Go, and Swift. More languages are coming soon based on user demand.

We're iOS-first right now, with Android coming in Q2 2025. Join our waitlist to be notified when it launches.

Our AI evaluates your explanations for key concepts, reasoning patterns, and logical flow—not just keywords. You can't just guess your way through. The system adapts its questions based on your understanding level.

Yes! We use secure sandboxed execution to run your code against real test cases. You can see exactly which tests pass or fail, just like in a real interview.

Absolutely. You can cancel your Pro subscription at any time with no questions asked. Your access continues until the end of your billing period.

Ready to Master Algorithms?

Start your free trial today. No credit card required.
Coming Soon to iOS.