I built a free application to help you simplify and structure your Leetcode grind

Edit: You can now autofill problem details by entering the Leetcode problem number, so you don't have to manually copy/paste anymore. Works with any Leetcode problem #1 to #3321 (which I think is all of them). Thanks u/Chamrockk, u/KayySean, and u/Strict-Inspection-99 for the suggestion/help

Hey everyone,

I’ve spent a lot of time grinding through Leetcode and realized that one weakness I have is staying organized and making sure I'm constantly improving every day, by either doing new problems or reviewing old ones. I was using physical notebooks, spreadsheets, spatial repetition apps like Anki, chatGPT tabs, notion, etc. and it was too messy.

So I spent the past few months building repcode.io, a free platform that cleanly combines all those tools (and more) in one place to help you stay organized and improve consistently.

Specifically, here’s what it does:

  1. Organize everything: Store problems, notes, commented solutions, and any other details in one place for easy reference. No more notebooks or spreadsheets needed.
  2. Spaced repetition: A (fully customizable) spaced repetition system (identical to Anki) helps you review concepts over time. Unlike basic flashcards, it includes an integrated coding environment so you actually code through the solution right in the app (or link it to Leetcode to solve there if you prefer their interface)
  3. AI analysis on your solutions: After solving a problem, you can have an AI (which uses the problem and its optimal solution as context) analyze your code, check the runtime, offer corrected code snippets, etc.
  4. Personalized data/analysis: Data from the spatial repetition feature is used to identify which patterns (Two Pointer, Sliding Window, etc) and specific problems you struggle with the most, so you can see what stuff you're naturally good at and what stuff you're not so good at and work on your weaknesses more

Me and some friends have been using it just on localhost for a while now, but recently I decided might as well make it more public in case others might find it useful too, why not, so I optimized/cleaned it up a bit and made it into a webapp. Feel free to check it out and let me know what you think! Any feedback or suggestions are welcome, as I'm still actively maintaining/developing it (check the changelog page to see recent updates)

Hope it's helpful for someone out there, happy coding and good luck with your interviews 🚀