Leetcode-maximum Depth of Binary Tree

Given a binary tree, find its maximum depth. The maximum depth is the number of nodes along, the longest path from the root node to the farthest leaf node.

/** * Definition for a binary tree node.  * public class TreeNode {*     int val, *     TreeNode left, *     TreeNode right; *     TreeNode (int x) {val = x;} *} */public class Solution {public    int maxDepth (TreeNode root) {        arraylist<treenode> prev = new arraylist< Treenode> ();                if (Root!=null) prev.add (root);        int depth=0;        while (!prev.isempty ()) {            arraylist<treenode> temp = new arraylist<treenode> ();            for (TreeNode Node:prev) {                if (node.left!=null) Temp.add (node.left);                if (node.right!=null) Temp.add (node.right);            }                prev = temp;            depth++;        }        return depth;}    }

　　

Leetcode-maximum Depth of Binary Tree