Given a binary tree, find its maximum depth.
The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.
1 class Solution { 2 public int maxDepth(TreeNode root) { 3 if(root == null) return 0; 4 int left_d = maxDepth(root.left)+1; 5 int right_d = maxDepth(root.right)+1; 6 return left_d > right_d ? left_d:right_d; 7 8 } 9 }
104. Maximum Depth of Binary Tree
原文：http://www.cnblogs.com/zle1992/p/7746010.html