Leetcode 297. Serialize and Deserialize Binary Tree
https://leetcode.com/problems/serialize-and-deserialize-binary-tree/
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.
Example:
You may serialize the following tree:
1
/ \
2 3
/ \
4 5
as "[1,2,3,null,null,4,5]"
Clarification: The above format is the same as how LeetCode 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.
- 构造和解析二叉树。学习python function用法。
- https://leetcode.com/problems/serialize-and-deserialize-binary-tree/discuss/74259/Recursive-preorder-Python-and-C%2B%2B-O(n)
- Built-in Functions — Python 3.7.4 documentation
- https://docs.python.org/3/library/functions.html?highlight=iter#iter
iter
(object[, sentinel])- Return an iterator object. The first argument is interpreted very differently depending on the presence of the second argument. Without a second argument, object must be a collection object which supports the iteration protocol (the
__iter__()
method), or it must support the sequence protocol (the__getitem__()
method with integer arguments starting at0
). If it does not support either of those protocols,TypeError
is raised. If the second argument, sentinel, is given, then object must be a callable object. The iterator created in this case will call object with no arguments for each call to its__next__()
method; if the value returned is equal to sentinel,StopIteration
will be raised, otherwise the value will be returned.
- https://docs.python.org/3/library/functions.html#next
next
(iterator[, default])- Retrieve the next item from the iterator by calling its
__next__()
method. If default is given, it is returned if the iterator is exhausted, otherwiseStopIteration
is raised.
- https://docs.python.org/3.7/library/stdtypes.html#str.split
str.
split
(sep=None, maxsplit=-1)- Return a list of the words in the string, using sep as the delimiter string. If maxsplit is given, at most maxsplit splits are done (thus, the list will have at most
maxsplit+1
elements). If maxsplit is not specified or-1
, then there is no limit on the number of splits (all possible splits are made).
- https://docs.python.org/3/library/functions.html?highlight=iter#iter