CSES 1131 Tree Diameter - Problem Statement

You are given a tree with $n$ nodes. Find the diameter: the maximum distance between any two nodes. Input: First line has $n$. Next $n-1$ lines each have two integers $a$ and $b$ representing an edge. Output: Single integer, the diameter. Constraints: $1 \leq n \leq 2 \times 10^5$ This is the classic tree diameter problem.

Solve it efficiently using two-BFS or DP. Both approaches run in $O(n)$ time and teach you core techniques for tree problems.

Space complexity is $O(n)$ for the data structures used.