104. Maximum Depth of Binary Tree

1 題目

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.

2 代碼

/**
 * 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) {
		return treeDeep(root);
	}

	public int treeDeep(TreeNode root) {
		if (root == null) {
			return 0;
		}
		if (root.left == null && root.right == null) {
			return 1;
		}
		int a = 1 + treeDeep(root.left);
		int b = 1 + treeDeep(root.right);
		return Math.max(a, b);
	}
}