103

1 files changed, 45 insertions, 0 deletions

diff --git a/103/main.py b/103/main.py
new file mode 100644
index 0000000..2c18d85
--- /dev/null
+++ b/103/main.py
@@ -0,0 +1,45 @@
+#!/usr/bin/env python
+
+from typing import Optional, List
+
+
+class TreeNode:
+    def __init__(self, val=0, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+
+
+class Solution:
+    def zigzagLevelOrder(self, root: Optional[TreeNode]) -> List[List[int]]:
+        if not root:
+            return []
+
+        res = []
+        q = [root]
+        left_to_right = True
+
+        while q:
+            level_size = len(q)
+            level = []
+
+            for i in range(level_size):
+                node = q.pop(0)
+
+                if left_to_right:
+                    level.append(node.val)
+                else:
+                    level = [node.val] + level
+
+                if node.left:
+                    q.append(node.left)
+                if node.right:
+                    q.append(node.right)
+            res.append(level)
+            left_to_right = not left_to_right
+        return res
+
+
+if __name__ == "__main__":
+    solution = Solution()
+    print(solution.zigzagLevelOrder())