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].
Note: The length of path between two nodes is represented by the number of edges between them.
/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ public class Solution { int d = 0; public int diameterOfBinaryTree(TreeNode root) { if (root == null) return 0; depth(root); return d; } private int depth(TreeNode node) { if (node == null) return 0; int left = depth(node.left); int right = depth(node.right); if (left + right > d) d = left + right; return left>right?left+1:right+1; } }