429:N 叉树的层序遍历

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huangge1199 2021-08-12 11:26:22 +08:00
parent 244d015888
commit 8262a1e4d0
3 changed files with 134 additions and 0 deletions

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@ -9,6 +9,7 @@ public class Node {
public Node random; public Node random;
public Node prev; public Node prev;
public Node child; public Node child;
public List<Node> children;
public Node(int val) { public Node(int val) {
this.val = val; this.val = val;

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@ -0,0 +1,100 @@
//给定一个 N 叉树返回其节点值的层序遍历即从左到右逐层遍历
//
// 树的序列化输入是用层序遍历每组子节点都由 null 值分隔参见示例
//
//
//
// 示例 1
//
//
//
//
//输入root = [1,null,3,2,4,null,5,6]
//输出[[1],[3,2,4],[5,6]]
//
//
// 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[[1],[2,3,4,5],[6,7,8,9,10],[11,12,13],[14]]
//
//
//
//
// 提示
//
//
// 树的高度不会超过 1000
// 树的节点总数在 [0, 10^4] 之间
//
// Related Topics 广度优先搜索
// 👍 170 👎 0
package leetcode.editor.cn;
import com.code.leet.entiy.Node;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;
//429:N 叉树的层序遍历
class NAryTreeLevelOrderTraversal {
public static void main(String[] args) {
//测试代码
Solution solution = new NAryTreeLevelOrderTraversal().new Solution();
}
//力扣代码
//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 List<List<Integer>> levelOrder(Node root) {
if (root == null) {
return new ArrayList<>();
}
Queue<Node> queue = new LinkedList<>();
queue.add(root);
List<List<Integer>> result = new ArrayList<>();
while (!queue.isEmpty()) {
int size = queue.size();
List<Integer> list = new ArrayList<>();
for (int i = 0; i < size; i++) {
Node node = queue.poll();
list.add(node.val);
List<Node> nodeList = node.children;
for (Node temp : nodeList) {
queue.add(temp);
}
}
result.add(list);
}
return result;
}
}
//leetcode submit region end(Prohibit modification and deletion)
}

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@ -0,0 +1,33 @@
<p>给定一个 N 叉树,返回其节点值的<em>层序遍历</em>。(即从左到右,逐层遍历)。</p>
<p>树的序列化输入是用层序遍历,每组子节点都由 null 值分隔(参见示例)。</p>
<p> </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>[[1],[3,2,4],[5,6]]
</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>[[1],[2,3,4,5],[6,7,8,9,10],[11,12,13],[14]]
</pre>
<p> </p>
<p><strong>提示:</strong></p>
<ul>
<li>树的高度不会超过 <code>1000</code></li>
<li>树的节点总数在 <code>[0, 10^4]</code> 之间</li>
</ul>
<div><div>Related Topics</div><div><li></li><li>广度优先搜索</li></div></div>\n<div><li>👍 170</li><li>👎 0</li></div>