#297

Serialize and Deserialize Binary Tree

hard· Treesruns: 0

Serialization is the process of converting a data structure into a sequence of bits so that it can be stored or transmitted, and reconstructed later. Design an algorithm to serialize and deserialize a binary tree. You may pick any string format you like.

wpm 0acc 100%time 0:000 / 790

class Codec:
    def serialize(self, root: TreeNode | None) -> str:
        result = []

        def dfs(node: TreeNode | None) -> None:
            if not node:
                result.append("N")
                return
            result.append(str(node.val))
            dfs(node.left)
            dfs(node.right)

        dfs(root)
        return ",".join(result)

    def deserialize(self, data: str) -> TreeNode | None:
        values = data.split(",")
        self.i = 0

        def dfs() -> TreeNode | None:
            if values[self.i] == "N":
                self.i += 1
                return None
            node = TreeNode(int(values[self.i]))
            self.i += 1
            node.left = dfs()
            node.right = dfs()
            return node

        return dfs()

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