Code RoomTrain set accuracy evaluation
EasyPrep Room Coding #4223

Train set accuracy evaluation

Vibe & agenticAlgorithms & data structuresMid–Senior~12 min

An AI wrote this quick model evaluation. It reports 99.2% accuracy and recommends shipping. As reviewer, why is this number meaningless?

Implement
holdout_accuracy(y_true: list[int], y_pred: list[int], in_train: list[bool]) → float
Examples
in[[1,0,1,0],[1,0,1,1],[true,true,false,false]]out0.5
in[[1,1],[1,1],[true,true]]out-1
What a strong answer looks like

Treat the AI’s output as a draft to verify, not an answer to trust. Name the specific flaw and the input that triggers it, say how you’d catch it (tests, edge cases, reading critically), and how you’d re-prompt or decompose to get it right.

0:00 of about 12 min

Vibe & agentic: describe the solution in plain language (or narrate it) and the coach grades your approach.

Which questions mattered is sealed until you submit. Telling you now would just be handing over the edge cases.