Leetcode
2020.04.30 11:59
559. Maximum Depth of N-ary Tree
조회 수 291 추천 수 0 댓글 0
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 = [1,null,3,2,4,null,5,6] Output: 3
Example 2:
Input: 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] Output: 5
Constraints:
- The depth of the n-ary tree is less than or equal to
1000. - The total number of nodes is between
[0, 10^4].
/*
// 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) {
Queue<Node> queue = new LinkedList<>();
int depth = 0;
if(root == null){
return depth;
}
queue.offer(root);
while(queue.size() > 0){
int size = queue.size();
for(int i=0; i<size; i++){
Node node = queue.poll();
for(int j=0; j<node.children.size(); j++){
queue.offer(node.children.get(j));
}
}
depth++;
}
return depth;
}
}/*
// 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) {
return findDepth(root, 1);
}
public int findDepth(Node node, int depth){
if(node == null){
return depth - 1;
}
if(node.children == null || node.children.size() == 0){
return depth;
}
int[] depths = new int[node.children.size()];
for(int i=0; i<depths.length; i++){
depths[i] = findDepth(node.children.get(i), depth + 1);
}
Arrays.sort(depths);
return depths[depths.length-1];
}
}
[문제] https://leetcode.com/problems/maximum-depth-of-n-ary-tree/
993. Cousins in Binary Tree
