CRTL+G Valhalla challange
Valhalla Challenge is a structured coding challenge program where developers design realistic, deterministic problems (in Rust, C, C++, or Go depending on track) for AI evaluation. Each challenge must include a concise real-world style description, base code that compiles but fails tests, a correct solution, and strong test coverage. The goal is to create high-quality problems that meaningfully test reasoning, edge cases, and implementation correctness not just simple algorithmic questions.