Node* Decoder::decodeTree()
{
    char ch;
    _fin >> ch;
    Node* node = new Node();
    if (ch == 'L')
    {
        _fin >> node->_bit;
        _fin.get(ch);
        node->_symbol = (unsigned char)ch;
        return node;
    }
    else
    {
        _fin >> node->_bit;
        node->_left = decodeTree();
        node->_right = decodeTree();
        return node;
    }
}