题解 | #二叉树的深度#

import java.util.*;
/**
public class TreeNode {
    int val = 0;
    TreeNode left = null;
    TreeNode right = null;

    public TreeNode(int val) {
        this.val = val;

    }

}
*/
public class Solution {
    public int TreeDepth(TreeNode root) {
        if (root == null) {
            return 0;
        }
        TreeNode node = root;
        int depth = 1;
        return depth(node, depth);
    }

    public int depth(TreeNode root, int depth) {
        if(root == null) {
            return depth - 1;
        }
        int left = depth(root.left, depth + 1);
        int right = depth(root.right, depth + 1);
        return left > right ? left : right;
    }
}