Serialize and Deserialize N-ary Tree

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Problem Description

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Solutions

Solution 1: C# (Best: 408 ms)

Metric	Value
Runtime	408 ms
Memory	51.9 MB
Date	2020-01-27

Solution

/*
// Definition for a Node.
public class Node {
    public int val;
    public IList<Node> children;

    public Node() {}

    public Node(int _val) {
        val = _val;
    }

    public Node(int _val, IList<Node> _children) {
        val = _val;
        children = _children;
    }
}
*/
public class Codec {

    // Encodes a tree to a single string.
    public string serialize(Node root)
    {
        List<string> nodes = new List<string>();
        SerializeHelper(root, nodes);
        return String.Join(",",nodes);
    }
    
    public void SerializeHelper(Node root, List<string> nodes)
    {
        if (root == null) return;
        nodes.Add($"{root.val}");
        nodes.Add($"{root.children.Count}");
        foreach (var child in root.children)
        {
            SerializeHelper(child, nodes);
        }
    }

    // Decodes your encoded data to tree.
    public Node deserialize(string data)
    {
        if(string.IsNullOrEmpty(data)) return null;
        Queue<string> nodes = new Queue<string>(data.Split(','));
        return DeserializeHelper(nodes);    
    
    }
    
    private Node DeserializeHelper(Queue<string> nodes)
    {
        Node root = new Node();
        root.val = Int32.Parse(nodes.Dequeue());
        int size = Int32.Parse(nodes.Dequeue());
        root.children = new List<Node>();
        for (int i = 0; i < size; i++)
        {
            root.children.Add(DeserializeHelper(nodes));
        }
        
        return root;
    }
}

// Your Codec object will be instantiated and called as such:
// Codec codec = new Codec();
// codec.deserialize(codec.serialize(root));

📜 1 more C# submission(s)

Submission (2020-01-27) — 680 ms, 54 MB

/*
// Definition for a Node.
public class Node {
    public int val;
    public IList<Node> children;

    public Node() {}

    public Node(int _val) {
        val = _val;
    }

    public Node(int _val, IList<Node> _children) {
        val = _val;
        children = _children;
    }
}
*/
public class Codec {

    // Encodes a tree to a single string.
    public string serialize(Node root)
    {
        List<string> nodes = new List<string>();
        SerializeHelper(root, nodes);
        return String.Join(",",nodes);
    }
    
    public void SerializeHelper(Node root, List<string> nodes)
    {
        if (root == null) return;
        nodes.Add($"{root.val}");
        nodes.Add($"{root.children.Count}");
        foreach (var child in root.children)
        {
            SerializeHelper(child, nodes);
        }
    }

    // Decodes your encoded data to tree.
    public Node deserialize(string data)
    {
        if(string.IsNullOrEmpty(data)) return null;
        Queue<string> nodes = new Queue<string>(data.Split(','));
        return DeserializeHelper(nodes);    
    
    }
    
    private Node DeserializeHelper(Queue<string> nodes)
    {
        Node root = new Node();
        root.val = Int32.Parse(nodes.Dequeue());
        int size = Int32.Parse(nodes.Dequeue());
        root.children = new List<Node>();
        for (int i = 0; i < size; i++)
        {
            root.children.Add(DeserializeHelper(nodes));
        }
        
        return root;
    }
}

// Your Codec object will be instantiated and called as such:
// Codec codec = new Codec();
// codec.deserialize(codec.serialize(root));

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Complexity Analysis

Approach	Time	Space
Solution	To be analyzed	To be analyzed