Draw my Code

Read a tiny C function. Paint its output.

Every day, you get one function, int f(int x, int y), and an empty 8×8 grid. For each cell, work out what the function returns, a number from 0 to 7, and paint the cell in that color.

You have 3 attempts. After each one, the game only tells you how many cells are wrong.

Some days it takes two minutes over coffee. Other days it's integer division, operator precedence, bit tricks, a loop or a recursion, and now and then a C surprise like -3 % 2.

What's in it

• A new puzzle every day at midnight, your time. Missed a day? The past week's puzzles stay open, and solving them keeps your streak.
• A 9-level tutorial that starts from zero. If you know what x / 2 means, you can play.
• Real C: gcc compiles every puzzle and checks it for undefined behavior, so the answer is what the code really returns.
• Stats, streaks, and a result grid you can share without spoiling the answer.
• Special puzzles on a few holidays.
• Mouse, touch or keyboard alone, and a "Show digits" option for colorblind players.
• On drawmycode.lonebee.games, it works offline and installs like an app on your phone.
• Free. No account, no ads, no cookies.

How to play

1. Read the function. x is the column and y the row, both from 0 to 7.
2. Pick a color, or press 0 to 7. Click or drag to paint; the arrow keys and Space work too.
3. Submit when you're sure.

Progress you make here is saved in this browser only, and it doesn't carry over to the website. Safari, and browsers on iPhone and iPad, may also forget it between visits.

For a streak that lasts, play on drawmycode.lonebee.games.