C · Java · Kotlin

Programming practice and tests, compiled in your browser.

Students write code in a full editor. Each program is compiled and judged on their own device, and every result is open for anyone to review.

gcd-and-lcm.cclang → wasm

1#include <stdio.h>

3long gcd(long a, long b) {

4if (b == 0) return a;

5return gcd(b, a % b);

Accepted8 / 8 tests3 ms · +200 pts

A fixed-code problem: only the highlighted body is editable.

The platform

Made for the classroom, from first exercise to final test.

Because judging happens in each browser, the platform needs almost no server capacity, and a whole class can submit at once without anyone waiting.

Clang for C and a full JVM for Java and Kotlin run on the student's machine as WebAssembly.

Lock the program and leave only function bodies to complete. Signatures can't be changed.

Scheduled assessments with a countdown, ICPC or partial scoring, and an optional language lock.

A global leaderboard and per-test standings that update as submissions are judged.

Every attempt is public with its verdict, timing and code. Each paste is traced to where it ended up.

Markdown and math statements, bulk test import, and expected outputs generated from a reference solution.

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