给定一个 N 叉树,找到其最大深度。
最大深度是指从根节点到最远叶子节点的最长路径上的节点总数。
N 叉树输入按层序遍历序列化表示,每组子节点由空值分隔(请参见示例)。
示例 1:
输入:root = [1,null,3,2,4,null,5,6] 输出:3
示例 2:
输入:root = [1,null,2,3,4,5,null,null,6,7,null,8,null,9,10,null,null,11,null,12,null,13,null,null,14] 输出:5
提示:
- 树的深度不会超过
1000
。 - 树的节点数目位于
[0, 104]
之间。
"""
# Definition for a Node.
class Node:
def __init__(self, val=None, children=None):
self.val = val
self.children = children
"""
class Solution:
def maxDepth(self, root: 'Node') -> int:
if root is None:
return 0
return 1 + max([self.maxDepth(child) for child in root.children], default=0)
/*
// Definition for a Node.
class Node {
public int val;
public List<Node> children;
public Node() {}
public Node(int _val) {
val = _val;
}
public Node(int _val, List<Node> _children) {
val = _val;
children = _children;
}
};
*/
class Solution {
public int maxDepth(Node root) {
if (root == null) {
return 0;
}
int ans = 1;
for (Node child : root.children) {
ans = Math.max(ans, 1 + maxDepth(child));
}
return ans;
}
}
/*
// Definition for a Node.
class Node {
public:
int val;
vector<Node*> children;
Node() {}
Node(int _val) {
val = _val;
}
Node(int _val, vector<Node*> _children) {
val = _val;
children = _children;
}
};
*/
class Solution {
public:
int maxDepth(Node* root) {
if (!root) return 0;
int ans = 1;
for (auto& child : root->children) ans = max(ans, 1 + maxDepth(child));
return ans;
}
};
/**
* Definition for a Node.
* type Node struct {
* Val int
* Children []*Node
* }
*/
func maxDepth(root *Node) int {
if root == nil {
return 0
}
ans := 1
for _, child := range root.Children {
ans = max(ans, 1+maxDepth(child))
}
return ans
}
func max(a, b int) int {
if a > b {
return a
}
return b
}