leetcode-mid-design-297. Serialize and Deserialize Binary Tree¶-NO -？？

mycode

将list转换成树的时候没有思路

参考：

deque 是双边队列（double-ended queue），具有队列和栈的性质，在 list 的基础上增加了移动、旋转和增删等

class Codec:

    def serialize(self, root):

        """Encodes a tree to a single string.

        :type root: TreeNode

        :rtype: str

        """

        vals = []

        def preOrder(root):

            if not root:

                vals.append('#')

            else:

                vals.append(str(root.val))

                preOrder(root.left)

                preOrder(root.right)

        preOrder(root)

        return ' '.join(vals)

    def deserialize(self, data):

        """Decodes your encoded data to tree.

        :type data: str

        :rtype: TreeNode

        """

        vals = collections.deque(val for val in data.split())

        def build():

            if vals:

                val = vals.popleft()

                if val == '#':

                    return None

                root = TreeNode(int(val))

                root.left = build()

                root.right = build()

                return root

        return build()

# Your Codec object will be instantiated and called as such:

# codec = Codec()

# codec.deserialize(codec.serialize(root))

其中queue可以用list替换

    def deserialize(self, data):

        """Decodes your encoded data to tree.

        :type data: str

        :rtype: TreeNode

        """

        print(data)

        self.vals = [val for val in data.split()]

        print(self.vals)

        def build():

            if self.vals:

                val = self.vals[0]

                self.vals = self.vals[1:]

                if val == '#':

                    return None

                root = TreeNode(int(val))

                root.left = build()

                root.right = build()

                return root

        return build()

疑惑

    def deserialize(self, data):

        """Decodes your encoded data to tree.

        :type data: str

        :rtype: TreeNode

        """

        print(data)

        vals = [val for val in data.split()]

        print(self.vals)

        def build():

            if vals:

                val = vals[0]

                vals[:] = vals[1:]

                print(vals)

                if val == '#':

                    return None

                root = TreeNode(int(val))

                root.left = build()

                root.right = build()

                return root

        return build()

Line 35: AttributeError: Codec instance has no attribute 'vals'

巴特西

leetcode-mid-design-297. Serialize and Deserialize Binary Tree¶-NO -？？

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