Question

Python

Given the root to a binary tree, implement serialize(root), which serializes the tree into a string, and deserialize(s), which deserializes the string back into the tree. For example, given the following Node class

class Node: def __init__(self, val, left=None, right=None):

self.val = val self.left = left self.right = right

The following test should pass:

node = Node('root', Node('left', Node('left.left')), Node('right')) assert deserialize(serialize(node)).left.left.val == 'left.left'

Answer 1

"""

Python

Given the root to a binary tree, implement serialize(root), which serializes the tree into a string, and deserialize(s), which deserializes the string back into the tree. For example, given the following Node class

class Node: def __init__(self, val, left=None, right=None):

self.val = val self.left = left self.right = right

The following test should pass:

node = Node('root', Node('left', Node('left.left')), Node('right')) assert deserialize(serialize(node)).left.left.val == 'left.left'

"""

class Node:
   def __init__(self, value):
       self.val = value
       self.left = None
       self.right = None

class Tree:
   def __init__(self):
       self.root = None

   def addNode(self, noe, value):
       if node == None:
           self.root = Node(value)
       else:
           if value < node.value:
               if not node.left:
                   node.left = Node(value)
               else:
                   self.addNodde(node.left, value)
           else:
               if not node.right:
                   node.right = Node(value)
               else:
                   self.adddNode(node.right, value)

def serialize(root):
   values = []
   def serializer(node):
       if not node:
           values.append('?')
       else:
           values.append(str(node.value))
           serializer(node.left)
           serializer(node.right)
   serializer(root)
   return ','.join(values)

def deserialize(s):
   values = iter(s.split(','))
   def deserializer():
       val = next(values)
       if val == '?':
           return None
       else:
           node = Node(int(val))
           node.left = deserializer()
           node.right = deserializer()
           return node
   return deserializer()

if __name__ == '__main__':
   #read input, number separated by comas
   numbers = [int(n) for n in input().split(',')]
   theTree = Tree()
   for number in numbers:
       theTree.addNode(theTree.root, number)
   s1 = serialize(theTree.root)
   s2 = serialize(deserialize(s1))
   print(s1)
   print(s2)
   assert s1 == s2