leetcode_gym/_problems/serializeTree.md

layout, title

layout	title
page	Serialize & Deserialize Tree

{% highlight python %}

class TreeNode:

def __init__(self, val):

    self.val = val
    self.left = None
    self.right = None

def serialize(root):

if not root:
    return "X"

leftRes = serialize(root.left)
rightRes = serialize(root.right)

return str(root.val) + "," + leftRes + "," + rightRes

def deserialize(str):

def dfs(nodesLeftList):

    # treat nodesLeft like a queue of incoming nodes to be serialized
    char = nodesLeftList.pop(0)

    if char=='X':
        return None

    node = TreeNode(char)
    node.left = dfs(nodesLeftList)
    node.right = dfs(nodesLeftList)

    return node

nodesLeftList = str.split(",")
n = dfs( nodesLeftList )        # this is the actual recursive call
return n

print("Serialize..") root = TreeNode(1) root.left = TreeNode(2) root.right = TreeNode(3) root.right.left = TreeNode(4) root.right.right = TreeNode(5) serialized = serialize(root) print(serialized) print()

print("Deserialize..") root2 = deserialize(serialized) print( root2.val ) print( root2.left.val ) print( root2.right.val ) print( root2.right.left.val ) print( root2.right.right.val )

{% endhighlight %}