[leetcode]104. Maximum Depth of Binary Tree二叉树最大深度

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.

Note: A leaf is a node with no children.

Example:

Given binary tree [3,9,20,null,null,15,7],

3 / \ 9 20 / \ 15 7

return its depth = 3.

 

题意：

求二叉树最大深度

 

Solution1： DFS

 

code

1 /** 2 * Definition for a binary tree node. 3 * public class TreeNode { 4 * int val; 5 * TreeNode left; 6 * TreeNode right; 7 * TreeNode(int x) { val = x; } 8 * } 9 */ 10 class Solution { 11 public int maxDepth(TreeNode root) { 12 if(root == null) return 0; 13 14 int maxLeft = maxDepth(root.left); 15 int maxRight = maxDepth(root.right); 16 17 return Math.max(maxLeft, maxRight)+1; 18 } 19 }

 

转载于:https://www.cnblogs.com/liuliu5151/p/10860179.html