Create binaryTreeLevelOrder.py

kanglicheng · web-flow · commit 93cd27af8c1d · 2018-03-22T13:06:20.000-07:00
diff --git a/Kangli/Trees/binaryTreeLevelOrder.py b/Kangli/Trees/binaryTreeLevelOrder.py
@@ -0,0 +1,51 @@
+class Solution():
+    def levelOrder(self, root):
+        ret = []
+        level = [root] 
+        while root and level:
+            currentNodes = []
+            nextLevel = []
+            for node in level:
+                currentNodes.append(node.val)
+                if node.left:
+                    nextLevel.append(node.left)
+                if node.right:
+                    nextLevel.append(node.right)
+            ret.append(currentNodes)
+            level = nextLevel      
+        return ret
+
+
+# Definition for a binary tree node.
+# class TreeNode(object):
+#     def __init__(self, x):
+#         self.val = x
+#         self.left = None
+#         self.right = None
+
+class Solution(object):
+    def levelOrder(self, root):
+        """
+        :type root: TreeNode
+        :rtype: List[List[int]]
+        """
+        if not root:
+            return []
+        queue, result = [root], [[root.val]]
+        
+        while queue:
+            queue_new = queue
+            queue = []
+            result_temp = []
+            for current in queue_new:
+                # current = queue_new.pop()
+                if current.left:
+                    queue.append(current.left)
+                    result_temp.append(current.left.val)
+                if current.right:
+                    queue.append(current.right)
+                    result_temp.append(current.right.val)
+            if len(result_temp)>0:
+                result.append(result_temp)
+                
+        return result
