Activity — Case Relay

Format for algorithmic lectures 09–20 · 12 minutes · one case, four teams.

1. Project one intermediate-or-harder case and split the board into four columns: Model · Plan · Code · Test.
2. Team 1 writes the model (inputs, outputs, constraints) in 2 minutes and passes the pen. Team 2 writes pseudocode from that model, and so on. Teams may not change earlier work — they inherit it, bugs included.
3. The final team also writes one test that the inherited plan would fail if it were wrong.
4. Debrief: run the pseudocode by hand on the final team's test. Where did the relay break? Almost always: an unclear model forced a guess downstream.

Why it works. It makes specification debt visible in 12 minutes — students feel their own ambiguity being inherited.

Pitfall. Choose a case with a genuinely small model (two-pointer or brute-force family). Sorting-family cases stall at the code step.