Question
You are given a functional graph as an array next where next[i] is the single outgoing edge from node i (every node has exactly one successor), or -1 if node i has no successor (a terminal). Starting from node 0 and repeatedly following next, return the length of the cycle you eventually enter, or 0 if the walk terminates (reaches a -1) without ever entering a cycle. Indices in next are valid node indices or -1.
cycle_length_from_zero(next_arr: list[int]) → int[[1,2,3,1]]out3State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.
Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.