node* node_cur = &root_node;

loop iterate over chars in word
{
    if(node_cur->children[c] == NULL)
    {
        node new_node;
        node_cur->children[c] = &new_node;
        node_cur = &new_node;
    }
}

node_cur->is_word = false;
for(int i = 0; i < 27; i++)
{
    node_cur->children[i] = NULL;
}

if(node_cur->children[c] == NULL)
    {
        node* new_node = malloc(sizeof(node));
        node_cur->children[c] = new_node;
        node_cur = new_node;
    }