标签：bfs png node color public eee rate lis off
Given an n-ary tree, return the level order traversal of its nodes‘ values.
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: [[1],[3,2,4],[5,6]]
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: [[1],[2,3,4,5],[6,7,8,9,10],[11,12,13],[14]]
Constraints:
1000[0, 10^4]class Solution { public List<List<Integer>> levelOrder(Node root) { List<List<Integer>> res = new ArrayList(); dfs(res, 0, root); return res; } public void dfs(List<List<Integer>> res, int h, Node root){ if(root == null) return; if(h == res.size()) res.add(new ArrayList()); res.get(h).add(root.val); for(Node node: root.children) dfs(res, h+1, node); } }
和普通level order没什么区别
class Solution { public List<List<Integer>> levelOrder(Node root) { List<List<Integer>> res = new ArrayList(); if(root == null) return res; Queue<Node> q = new LinkedList(); q.offer(root); while(!q.isEmpty()){ List<Integer> list = new ArrayList(); int si = q.size(); for(int i = 0; i < si; i++){ Node cur = q.poll(); list.add(cur.val); for(Node node: cur.children){ q.offer(node); } } res.add(list); } return res; } }
欸？bfs比dfs慢，
429. N-ary Tree Level Order Traversal
标签：bfs png node color public eee rate lis off
原文地址：https://www.cnblogs.com/wentiliangkaihua/p/13278165.html
