428

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

    Node() {}

    Node(int _val) {
        val = _val;
    }

    Node(int _val, vector<Node*> _children) {
        val = _val;
        children = _children;
    }
};
*/

class Codec {
public:
    // Encodes a tree to a single string.
    string serialize(Node* root) {
        // If tree is null.
        if(!root) return "#";

        // Add current node's value and then it's length.
        string repr = "";
        repr += to_string(root->val)+',';
        repr += to_string((root->children).size())+',';

        // Add each child's representation.
        for(int i=0; i<(root->children).size(); i++)
            repr += serialize((root->children)[i]);
        return repr;
    }

    // Decodes your encoded data to tree.
    Node* deserialize(string data) {
        return dserialize(data);
    }

    Node* dserialize(string &data){
        // If tree is null.
        if(data[0] == '#') return NULL;

        // Create node with value.
        int pos = data.find(',');
        int val = stoi(data.substr(0, pos));
        data = data.substr(pos+1);
        Node *node = new Node(val);

        // Find number of children and recurse over each.
        pos = data.find(',');
        int numChild = stoi(data.substr(0, pos));
        data = data.substr(pos+1);
        for(int i=0; i<numChild; i++)
            (node->children).push_back(dserialize(data));
        return node;
    }
};

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