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Serialize and Deserialize Binary Tree

Explore techniques to serialize a binary tree into a list of integers and deserialize it back to reconstruct the exact tree. Understand how to handle tree traversal and data structure manipulation to solve this common coding interview problem effectively.

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Statement

Serialize a given binary tree to a file and deserialize it back to a tree. Make sure that the original and the deserialized trees are identical.

  • Serialize: Write the tree to a file.

  • Deserialize: Read from a file and reconstruct the tree in memory.

Serialize the tree into a list of integers, and then, deserialize it back from the list to a tree. For simplicity’s sake, there’s no need to write the list to the files.

Constraints:

  • The number of nodes in the tree is in the range [0,500][0, 500].
  • −1000≤-1000 \leq Node.value ≤1000\leq 1000

Examples

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Understand the problem

Let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

Serialize and Deserialize Binary Tree

1.

What is the serialized output of this tree using level order traversal?

          __ 350 
	     |
	  __ 75 ______ 
	 |            |
	 25 _     ___ 200 
	     |   |
	     50  100
A.

[350, 75, 25, 50, 200, 100]

B.

[350, 75, 25, 200, 50, 100]

C.

[25, 50, 75, 100, 200, 350]

D.

[50, 25, 100, 200, 75, 350]

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Figure it out!

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Sequence - Vertical
Drag and drop the cards to re-arrange them in the correct sequence
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Try it yourself

Implement your solution in SerializeDeserialize.java in the following coding playground.

Java
usercode > SerializeDeserialize.java
// Definiton of a binary tree node class
// class TreeNode<T> {
//     T data;
//     TreeNode<T> left;
//     TreeNode<T> right;
//     TreeNode(T data) {
//         this.data = data;
//         this.left = null;
//         this.right = null;
//     }
// }
import java.util.*;
import ds_v1.BinaryTree.TreeNode;
public class SerializeDeserialize{
    public static List<String> serialize(TreeNode<Integer> root) {
        
        // Replace this placeholder return statement with your code
        return new ArrayList<>();
    }
    public static TreeNode<Integer> deserialize(List<String> stream){
        
        // Replace this placeholder return statement with your code
        return new TreeNode<Integer>(0);
    }
}
Serialize and Deserialize Binary Tree