Binary Tree Level Order Traversal 2021-06-07 20:27
public List<List<Integer>> levelOrder(TreeNode root) {
List<List<Integer>> res = new LinkedList<>();
if (root == null) {
return res;
}
Queue<TreeNode> queue = new LinkedList<>();
queue.add(root);
while (!queue.isEmpty()) {
res.add(allChild(queue));
}
return res;
}
private List<Integer> allChild(Queue<TreeNode> queue) {
List<Integer> list = new LinkedList<>();
int size = queue.size();
for (int i = 0; i < size; i++) {
TreeNode curr = queue.poll();
if (curr == null) {
return list;
}
if (curr.left != null) {
queue.add(curr.left);
}
if (curr.right != null) {
queue.add(curr.right);
}
list.add(curr.val);
}
return list;
}
| Runtime | Memory |
|---|---|
| 0 ms | 39.2 MB |
EOF