Question

I have the following class:

public class Category {
    public string Name { get; set; }
    public Category Parent { get; set; }
    public string Url { get; set; }
    public List<Category> Children { get; set; }
}

Now given an instance of a Category and url. I wish to get the Category where the url matches the category or any of it’s children (or their children etc).

Therefore my function would have the following signature:

public Category FindCategory(Category category, string url);

I know recursion is the way to go and i have managed to come up with a solution. However i’ve definitely seen it done better but i can’t find where. I’d appreciate it if someone could show me the easiest and cleanest way to achieve this.

Thanks

Answer 1

Here is a simple recursive algorithm:

public Category FindCategory(Category category, string url)
{
    if(category.Url == url)
    {
        return category;
    }

    Category solution = null;    

    foreach(Category child in category.Children)
    {
        solution = FindCategory(child, url);
        if(solution != null)
        {
            return solution;
        }
    }

    return null;
}