From de087c0467d34a209513d7f4dd21dcba5d404001 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 17 Feb 2026 00:34:37 +0000
Subject: [PATCH 1/2] Initial plan


From daf0e651be2551e7d8bee9dd2ff3bd47b29f8f38 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 17 Feb 2026 00:36:12 +0000
Subject: [PATCH 2/2] Add None checks before appending children to prevent
 enqueueing None values

Co-authored-by: cd155 <16947266+cd155@users.noreply.github.com>
---
 src/tree/binary_tree_level_order_traversal.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/tree/binary_tree_level_order_traversal.py b/src/tree/binary_tree_level_order_traversal.py
index db1dc44..6704eab 100644
--- a/src/tree/binary_tree_level_order_traversal.py
+++ b/src/tree/binary_tree_level_order_traversal.py
@@ -48,8 +48,10 @@ def levelOrder(self, root):
             for n in nodes:
                 if n:
                     level.append(n.val)
-                    new_nodes.append(n.left)
-                    new_nodes.append(n.right)
+                    if n.left:
+                        new_nodes.append(n.left)
+                    if n.right:
+                        new_nodes.append(n.right)
             if level:
                 result.append(level)
             if new_nodes: