Hard
Subtopics
binary-tree·breadth-first-search·depth-first-search·design·string·tree
Companies
amazon·apple·bloomberg·citadel·ebay·expedia·facebook·google·groupon·indeed·linkedin·microsoft·oracle·qualtrics·quora·salesforce·snapchat·tableau·uber·vmware·yahooLast updated: Mar 4, 2025
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.
Clarification: The input/output 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.
publicclassCodec {
// Encodes a tree to a single string.public String serialize(TreeNode root) {
}
// Decodes your encoded data to tree.public TreeNode deserialize(String data) {
}
}
Now, we can serialize it to a string like these, treating nulls as ‘#’:
1
20,8,#,4,12,#,#,10,14,#,#,#,#
So, whenever a treenode is null, we have # and we stop tracking the children.
When deserialize the string, I assign left and right child for each not-null node, and add the not-null children to the queue, waiting to be handled later.