Coding (Algo)

Find the First Repeated Link

Algorithm: Cycle detection Difficulty: Medium Time: 35 minutes

Goal

Return the index where the reachable chain first enters its cycle using constant auxiliary space or null if the chain terminates.

What this task practices

Find the First Repeated Link is a coding (algo) interview exercise that trains prompt interpretation, explicit assumptions, a concrete response, and a clear explanation of tradeoffs. The catalog marks it as medium difficulty. It focuses on Technical Reasoning, Testing, Validation. The signed-in workspace provides the tools for the round and evaluates the attempt against task-specific criteria. Reference solutions, hidden checks, evaluator instructions, and candidate work remain private.