leetcode-二叉树的最大深度

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
class Solution {
    private int maxdeep = 0;
    public int maxDepth(TreeNode root) {
        this.dfs(root,0);
        return this.maxdeep;
    }
    public void dfs(TreeNode node,int deep){
        if(node==null){
            this.maxdeep = Math.max(this.maxdeep,deep);
            return ;
        }
        this.dfs(node.left,deep+1);
        this.dfs(node.right,deep+1);
    }
}

解题思路:

这道题还是非常简单，最节点的左右子树进行递归并记录递归层数，直到节点为null,判断当前层数是否是新的最大层数即可。