Trie дерево

#include <iostream>
#include <vector>
#include <string>
#include <iomanip>
using namespace std;

struct Node
{
    vector<Node*> children;
    vector<size_t> keys;
    char symbol = '+';
};

class TrieTree
{
    Node* root;
    void addMethod(Node* node, const string& word, const size_t& id, const size_t& key)
    {
        if (id >= word.size())
            return;

        for (size_t j = 0; j < node->children.size(); j++)
            if (node->children[j]->symbol == word[id])
            {
                node->children[j]->keys.push_back(key);
                addMethod(node->children[j], word, id + 1, key);
                return;
            }

        Node* tmp = new Node();
        tmp->keys.push_back(key);
        tmp->symbol = word[id];

        node->children.push_back(tmp);
        addMethod(tmp, word, id + 1, key);
    }

    void getByKeyMethod(Node* node, string& word, const size_t& key)
    {

        for (size_t i = 0; i < node->children.size() ; i++)
        {
            for (size_t j = 0; j < node->children[i]->keys.size(); j++)
            {
                if (node->children[i]->keys[j] == key)
                {
                    word += node->children[i]->symbol;
                    getByKeyMethod(node->children[i], word, key);
                    return;
                }

            }
            return;
        }
    }

public:
    TrieTree()
    {
        root = new Node;
        root->symbol = '-';
    }

    void add(const string& word, const size_t& key)
    {
        Node* it = root;
        addMethod(root, word, 0, key);
    }

    string getByKey(const size_t& key)
    {
        string word;
        getByKeyMethod(root, word, key);
        return word;
    }
};

int main()
{
    TrieTree a;
    a.add("word", 1);
    a.add("wordm", 2);
    cout << a.getByKey(2);
    return 0;
};