The Alternating Neon Path

You are given a tree representing a network of neon-lit tunnels. Each edge (tunnel) has a color. A 'vibrant path' is a simple path in the tree such that no two adjacent edges on the path have the same color. Your task is to find the length (number of edges) of the longest vibrant path in the tree. Input Format: - Line 1: An integer N, the number of nodes (1-indexed). - Next N-1 lines: Three integers u, v, c representing an edge between u and v with color c. Output Format: - A single integer representing the length of the longest vibrant path. Example: Input: 5 1 2 1 2 3 2 3 4 2 3 5 1 Output: 3 (The path 1-2-3-5 has colors 1, 2, 1 which are alternating. Length 3.)