Proof of correctness: Algorithm for diameter of a tree in graph theory

Question

In order to find the diameter of a tree I can take any node from the tree, perform BFS to find a node which is farthest away from it and then perform BFS on that node. The g

Answer 1

1:procedureTreeDiameter(T)

2:pick an arbitrary vertex v where v∈V

3:u = BFS ( T, v )

4:t = BFS ( T, u )

5:return distance ( u, t )

Result: Complexity = O(|V|)