leetcode 559. Maximum Depth of N-ary Tree
Given a n-ary 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.
Nary-Tree input serialization is represented in their level order traversal, each group of children is separated by the null value (See examples).
Example 1:
Input: root =
Output: 3
Example 2:
Input: root =
Output: 5
Constraints:
The depth of the n-ary tree is less than or equal to 1000.
The total number of nodes is between .
/*
// 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 {
int max;
public int maxDepth(Node root) {
if(root == null) return 0;
int dep = 1;
dfs(root,dep);
return max;
}
public void dfs(Node root, int depth){
if(depth > max) max = depth;
if(root.children.size() == 0) return;
int len = root.children.size();
for(int i = 0; i< len; i++){
if(root.children.get(i) != null){
dfs(root.children.get(i), depth+1);
}
}
}
}
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