Prep RoomSign inStart free
Code RoomSave format field order fragile
MediumPrep Room Coding #4300

Save format field order fragile

Vibe & agenticAlgorithms & data structuresMid–Senior~17 min

An AI agent wrote save/load for an RPG in C# using BinaryFormatter-style field-order serialization. It works in testing. After you ship a patch that adds one field to the player struct, every player's existing save loads with corrupted inventories and wrong stats. Review the serializer and explain the save-game bug.

Implement
read_save_record(record: str) → list[str]
Examples
in["2,5,100,3,11,12,13,250,40"]out["level=5","health=100","inventory=11;12;13","gold=250","mana=40"]
in["1,5,100,3,11,12,13,250"]out["level=5","health=100","inventory=11;12;13","gold=250","mana=0"]
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 17 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.