BEGINNER · PROGRAM
aff_a
Write a complete C programme that prints the lowercase letter a followed by a newline. The published subject permits write.
C track · beta
Build precise C fundamentals
The current track begins with exact output and the write function. It contains 1 published exercise and 9 planned curriculum outlines; only published material is presented as ready to practise.
Published now
1 exercise
Curriculum outlines
10 beginner entries
Exercise formats
7 programmes · 3 functions
Storage
Current browser only
Published exercise
Ready to explore
Beta
Rules and progress
What an account changes today
Allowed functions
Each published subject lists its allowed functions. c0den displays that rule today, but enforcement waits for the isolated evaluator.
Drafts and activity
A signed-in workspace stores account-scoped drafts and in-progress activity in the current browser. It does not sync between devices.
Unlocking and XP
No exercise is unlocked and no XP is awarded from local activity. Both require a future trusted passing submission.
Evaluation status
Simulated foundations and planned evaluator capabilities
The authenticated workspace can persist a mock submission and queue lifecycle without evaluating source. User code is never executed by the Next.js application; real evaluator capabilities need a separate restricted service.
Evaluation preview
SimulationSee an illustrative evaluation report that does not compile, execute, or grade submitted code.
Persisted mock submissions
SimulationStore an authenticated source snapshot and exercise a deterministic queue flow without compiling, grading, XP, completion, or unlocking.
Isolated C compilation
PlannedCompile submitted C code in a separate restricted evaluator service.
Public tests
PlannedRun evaluator-backed visible tests without awarding completion.
Hidden tests
PlannedRun private evaluator tests as part of a trusted final submission.
Memory checks
PlannedInspect evaluator-run programs for supported memory-safety failures.
Trusted XP
PlannedAward persistent XP only after an evaluator-verified completion.
Exercise unlocking
PlannedUnlock later exercises from trusted prerequisite completion.
Cross-device learning sync
PlannedSynchronize drafts and learning activity between signed-in devices.