題目描述
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.
/**
* Definition for binary tree
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
public class Solution {
public int maxDepth(TreeNode root) {
if (root==null) {
return 0;
}
return binaryTreeDepth(root);
}
public int binaryTreeDepth(TreeNode root) {
if (root==null) {
return 0;
}
int leftDepth = binaryTreeDepth(root.left)+1;
int rightDepth = binaryTreeDepth(root.right)+1;
return Math.max(leftDepth, rightDepth);
}
}