Java | Leetcode Java题解之第429题N叉树的层序遍历
题目：
题解：
class Solution {
public List<List<Integer>> levelOrder(Node root) {
if (root == null) {
return new ArrayList<List<Integer>>();
}
List<List<Integer>> ans = new ArrayList<List<Integer>>();
Queue<Node> queue = new ArrayDeque<Node>();
queue.offer(root);
while (!queue.isEmpty()) {
int cnt = queue.size();
List<Integer> level = new ArrayList<Integer>();
for (int i = 0; i < cnt; ++i) {
Node cur = queue.poll();
level.add(cur.val);
for (Node child : cur.children) {
queue.offer(child);
}
}
ans.add(level);
}
return ans;
}
}