297. Serialize and Deserialize Binary Tree 二叉树的序列化与反序列化

【LeetCode】297. Serialize and Deserialize Binary Tree 解题报告(Python)

标签: LeetCode



Serialization is the process of converting a data structure or object into a sequence of bits so that it can be stored in a file or memory buffer, or transmitted across a network connection link to be reconstructed later in the same or another computer environment.

Design an algorithm to serialize and deserialize a binary tree. There is no restriction on how your serialization/deserialization algorithm should work. You just need to ensure that a binary tree can be serialized to a string and this string can be deserialized to the original tree structure.

For example, you may serialize the following tree

   / \
  2   3
     / \
    4   5

as "[1,2,3,null,null,4,5]", just the same as how LeetCode OJ serializes a binary tree. You do not necessarily need to follow this format, so please be creative and come up with different approaches yourself.

Note: Do not use class member/global/static variables to store states. Your serialize and deserialize algorithms should be stateless.




449. Serialize and Deserialize BSTopen in new window多么的像呀!之前我说,只知道前序遍历是没法确定一个树的,我说的不严谨。如果前序遍历的过程中记录下哪些位置是空节点的话,就是可以确定这棵树的。LeetCode的官方树的构建就是这样的。


# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

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:
        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))


2018 年 3 月 15 日 --雾霾消散,春光明媚