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 longestpath 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].
1 public class Solution { 2 int max = 0; 3 4 public int diameterOfBinaryTree(TreeNode root) { 5 maxDepth(root); 6 return max; 7 } 8 9 private int maxDepth(TreeNode root) { 10 if (root == null) return 0; 11 12 int left = maxDepth(root.left); 13 int right = maxDepth(root.right); 14 15 max = Math.max(max, left + right); 16 17 return Math.max(left, right) + 1; 18 } 19 }
原文：https://www.cnblogs.com/zle1992/p/9332910.html