二叉树相关 102题 二叉树的层序遍历

Author: imbaliking

new_issue/binary-tree-level-order-traversal.py

@@ -0,0 +1,29 @@
+def levelOrder(root):
+    """
+    :type root: TreeNode
+    :rtype: List[List[int]]
+    """
+    if root is None:
+        return []
+    queue = [root]
+    ret = [[]]
+    last_father = root
+    while len(queue) != 0:
+        op_node = queue[0]
+        queue.remove(op_node)
+        if last_father is not None and (last_father.left == op_node or last_father.right == op_node):
+            local_ret = [op_node.val]
+            ret.append(local_ret)
+            last_father = None
+        else:
+            ret[-1].append(op_node.val)
+        if op_node.left is not None:
+            queue.append(op_node.left)
+            if last_father is None:
+                last_father = op_node
+        if op_node.right is not None:
+            queue.append(op_node.right)
+            if last_father is None:
+                last_father = op_node
+
+    return ret