Given a binary tree, you need to compute the length of the diameter of the tree. The diameter of a binary tree is the length of the longest path between any two nodes in a tree. This path may or may not pass through the root.
Example:
Given a binary tree
1
/ 2 3
/ \
4 5
Return 3, which is the length of the path [4,2,1,3] or [5,2,1,3].
Note: The length of path between two nodes is represented by the number of edges between them.
方法一：递归
此问题在104题基础上求最短路径
543. Diameter of Binary Tree（两节点的最长路径）
原文：https://www.cnblogs.com/shaer/p/10563931.html