559:N 叉树的最大深度

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轩辕龙儿 2022-03-23 22:23:24 +08:00
parent 57e4bc86b3
commit 8fb44308b0
3 changed files with 146 additions and 0 deletions

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@ -1,7 +1,9 @@
package com.code.leet.entiy;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;
public class Node {
public int val;
@ -37,6 +39,22 @@ public class Node {
this.child = child;
}
public Node(List<Integer> list) {
this.val = list.get(0);
Queue<Node> queue = new LinkedList<>();
queue.add(this);
for (int i = 2; i < list.size(); i++) {
Node root = queue.poll();
root.children = new ArrayList<>();
while (i < list.size() && list.get(i) != null) {
Node node = new Node(list.get(i));
root.children.add(node);
queue.add(node);
i++;
}
}
}
public Node setHead(List<Integer> list, List<Integer> index) {
Node head = new Node(list.get(0));
int i = 1;

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//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, 10] 之间
//
// Related Topics 深度优先搜索 广度优先搜索 👍 257 👎 0
package leetcode.editor.cn;
import com.code.leet.entiy.Node;
import java.util.Arrays;
//559:N 叉树的最大深度
public class MaximumDepthOfNAryTree {
public static void main(String[] args) {
Solution solution = new MaximumDepthOfNAryTree().new Solution();
Node root = new Node(Arrays.asList(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));
solution.maxDepth(root);
}
//leetcode submit region begin(Prohibit modification and deletion)
/*
// 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;
}
dfs(root, 0);
return max;
}
int max = 0;
private void dfs(Node root, int deep) {
deep++;
for (Node child : root.children) {
dfs(child, deep);
}
max = Math.max(max, deep);
}
}
//leetcode submit region end(Prohibit modification and deletion)
}

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<p>给定一个 N 叉树,找到其最大深度。</p>
<p class="MachineTrans-lang-zh-CN">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。</p>
<p class="MachineTrans-lang-zh-CN">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)。</p>
<p class="MachineTrans-lang-zh-CN"> </p>
<p><strong>示例 1</strong></p>
<p><img src="https://assets.leetcode.com/uploads/2018/10/12/narytreeexample.png" style="width: 100%; max-width: 300px;" /></p>
<pre>
<strong>输入:</strong>root = [1,null,3,2,4,null,5,6]
<strong>输出:</strong>3
</pre>
<p><strong>示例 2</strong></p>
<p><img alt="" src="https://assets.leetcode.com/uploads/2019/11/08/sample_4_964.png" style="width: 296px; height: 241px;" /></p>
<pre>
<strong>输入:</strong>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]
<strong>输出:</strong>5
</pre>
<p> </p>
<p><strong>提示:</strong></p>
<ul>
<li>树的深度不会超过 <code>1000</code></li>
<li>树的节点数目位于 <code>[0, 10<sup>4</sup>]</code> 之间。</li>
</ul>
<div><div>Related Topics</div><div><li></li><li>深度优先搜索</li><li>广度优先搜索</li></div></div><br><div><li>👍 257</li><li>👎 0</li></div>