Binary_Tree_Level_Order_traversal

CodingProgrammer · CodingProgrammer · commit b72278358e81 · 2017-12-24T13:57:32.000+08:00
diff --git a/102_Binary_Tree_Level_Order_Traversal.py b/102_Binary_Tree_Level_Order_Traversal.py
@@ -0,0 +1,23 @@
+# Definition for a binary tree node.
+# class TreeNode:
+#     def __init__(self, x):
+#         self.val = x
+#         self.left = None
+#         self.right = None
+
+class Solution:
+    def levelOrder(self, root):
+        """
+        :type root: TreeNode
+        :rtype: List[List[int]]
+        """
+        ans = []
+        def preOrder(root, level):
+            if None != root :
+                if len(ans) < level + 1:
+                    ans.append([])
+                ans[level].append(root.val)
+                preOrder(root.left, level + 1)
+                preOrder(root.right, level + 1)
+        preOrder(root, 0)
+        return ans
