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Coding Challenges

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Every challenge here is drawn from the live Code Royale pool. Review a question, then head to the arena to answer under pressure against a real opponent — 3-minute matches, Elo ranking, and badge tiers on the line.

Coding Challenges

unordered_map pointer survives rehash

Reference to vector element across growth

Iterator invalidation while erasing in a vector loop

Iterator invalidation after unordered_map insert

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