LintCode 97. Maximum Depth of Binary Tree 原创Java参考解答
问题描述
http://www.lintcode.com/en/problem/maximum-depth-of-binary-tree/
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.
Example
Given a binary tree as follow:
1
/ \
2 3
/ \
4 5
The maximum depth is 3.
解题思路
题目是求二叉树的最大深度。
用分治思想解决这道题。分开算出左右子树的深度，再合并计算整棵树的最大深度。
参考代码
/**
* Definition of TreeNode:
* public class TreeNode {
* public int val;
* public TreeNode left, right;
* public TreeNode(int val) {
* this.val = val;
* this.left = this.right = null;
* }
* }
*/
public class Solution {
/**
* @param root: The root of binary tree.
* @return: An integer.
*/
public int maxDepth(TreeNode root) {
if (root == null) {
return 0;
}
int leftDepth = maxDepth(root.left);
int rightDepth = maxDepth(root.right);
return Math.max(leftDepth, rightDepth) + 1;
}
}