Python实现的序列化和反序列化二叉树算法示例

本文实例讲述了Python实现的序列化和反序列化二叉树算法。分享给大家供大家参考，具体如

本文实例讲述了Python实现的序列化和反序列化二叉树算法。分享给大家供大家参考，具体如下：

题目描述

请实现两个函数，分别用来序列化和反序列化二叉树

序列化二叉树

先序遍历二叉树

 def recursionSerialize(self, root):
 series = ''
 if root == None:
 series += ',$'
 else:
 series += (',' + str(root.val))
 series += self.recursionSerialize(root.left)
 series += self.recursionSerialize(root.right)
 return series
 def Serialize(self, root):
 return self.recursionSerialize(root)[1:]

结果：

root = TreeNode(11)
root.left = TreeNode(2)
root.right = TreeNode(3)
series = Solution().Serialize(root)
print(series)
>>>11,2,$,$,3,$,$

反序列化

先构建根节点，然后左节点，右节点，同样是递归

注意由于使用的是字符串的表示形式，可以先转化为list，

print(series.split(','))
>>>['11', '2', '$', '$', '3', '$', '$']

然后再处理就不需要将大于10的数字转换过来了：

 def getValue(self, s, sIndex): #处理超过10的数字，将数字字符转变为数字
 val = 0
 while ord(s[sIndex]) <= ord('9') and ord(s[sIndex]) >= ord('0'):
 val = val * 10 + int(s[sIndex])
 sIndex += 1
 return val, sIndex - 1

下面是反序列化的递归函数：

 def Deserialize(self, s):
 if self.sIndex < len(s):
 if s[self.sIndex] == ',':
 self.sIndex += 1
 if s[self.sIndex] == '$':
 return None
 val, self.sIndex = self.getValue(s, self.sIndex)
 treeNode = TreeNode(val)
 self.sIndex += 1
 treeNode.left = self.Deserialize(s)
 self.sIndex += 1
 treeNode.right = self.Deserialize(s)
 return treeNode

完整解法

class TreeNode:
 def __init__(self, x):
 self.val = x
 self.left = None
 self.right = None
class Solution:
 def __init__(self):
 self.sIndex = 0
 def recursionSerialize(self, root):
 series = ''
 if root == None:
 series += ',$'
 else:
 series += (',' + str(root.val))
 series += self.recursionSerialize(root.left)
 series += self.recursionSerialize(root.right)
 return series
 def Serialize(self, root):
 return self.recursionSerialize(root)[1:]
 def getValue(self, s, sIndex): #处理超过10的数字，将数字字符转变为数字
 val = 0
 while ord(s[sIndex]) <= ord('9') and ord(s[sIndex]) >= ord('0'):
 val = val * 10 + int(s[sIndex])
 sIndex += 1
 return val, sIndex - 1
 def Deserialize(self, s):
 if self.sIndex < len(s):
 if s[self.sIndex] == ',':
 self.sIndex += 1
 if s[self.sIndex] == '$':
 return None
 val, self.sIndex = self.getValue(s, self.sIndex)
 treeNode = TreeNode(val)
 self.sIndex += 1
 treeNode.left = self.Deserialize(s)
 self.sIndex += 1
 treeNode.right = self.Deserialize(s)
 return treeNode