Medium
考Binary Tree Level Order Traversal,简单秒.
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
class Solution {
public List<Integer> largestValues(TreeNode root) {
List<Integer> res = new ArrayList<>();
if (root == null){
return res;
}
Queue<TreeNode> queue = new LinkedList<>();
queue.offer(root);
while (!queue.isEmpty()){
int size = queue.size();
int max = Integer.MIN_VALUE;
for (int i = 0; i < size; i++){
TreeNode curt = queue.poll();
if (curt.val > max){
max = curt.val;
}
if (curt.left != null){
queue.offer(curt.left);
}
if (curt.right != null){
queue.offer(curt.right);
}
}
res.add(max);
}
return res;
}
}
