[LeetCode] Maximum Depth of Binary Tree 二叉樹的最大深度
阿新 • • 發佈:2018-11-27
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.
Note: A leaf is a node with no children.
Example:
Given binary tree [3,9,20,null,null,15,7]
,
3 / \ 9 20 / \ 15 7
return its depth = 3.
程式碼:
// 104. Maximum Depth of Binary Tree // https://leetcode.com/problems/maximum-depth-of-binary-tree/description/ // 時間複雜度: O(n), n是樹中的節點個數 // 空間複雜度: O(h), h是樹的高度 class Solution { // Definition for a binary tree node. public class TreeNode { int val; TreeNode left; TreeNode right; TreeNode(int x) { val = x; } } public int maxDepth(TreeNode root) { if(root == null) return 0; return 1 + Math.max(maxDepth(root.left), maxDepth(root.right)); } }