Algorithm
Guided program simulation
Follow the state, one step at a time.
Read the highlighted line, predict every value in the current row, and check the complete state before advancing. The trace table makes changes to variables, conditions, indexed data, and output visible.
- Read the prompt and starting state.
- Follow the highlighted line.
- Enter the program state for that step.
- Correct mistakes before continuing.
Learner identity
Identify your work before tracing.
Your name is locked when you check the first step. The completed PNG uses this identity and can be downloaded only once for that trace.
Privacy: this information stays in this browser and is not sent to a server.
Program state
Trace table
Trace complete
You followed every state transition.
Completion evidence
Download a trace screenshot
The PNG shows the locked learner identity, completion ID, timestamps, problem details, and correct trace table. It can be generated once for this completed trace.