c# - Finding a path of recursion

Question

Hello everyone I have a small problem and I feel a little bit stuck. I manage to get the object that I want, but I don't know how to return the path to that object (how I found it). My code looks like this at the moment:

P.S what I mean by path: every single item has it's name and id. I manage to find an object with id (which I give when call for recursion) and when I find it, I need to create string and add all of it's parents names to it and return it.

protected void FindPath(int depth, int id, InventLocationViewModel currentLocation)
    {
        if (depth < 0)
            return;

        if (currentLocation.Id == id)
        {
            selectedLocation = currentLocation;
            return;
        }

        foreach (var child in currentLocation.ChildInventLocations)
        {
            FindPath(depth - 1, id, child);
        }
    }

    protected void SelectedLocation(RecursiveSelectObject args)
    {
        currentLocation = locations.InventLocations.FirstOrDefault(e => e.Id == locationId.Value);

        FindPath(args.Level, args.Id, currentLocation);

        if (selectedLocation.Id == args.Id)
        {

        }
    }

question from:https://stackoverflow.com/questions/65906631/finding-a-path-of-recursion

Answer 1

You know what you want to keep on the way out:

protected List<InventLocationViewModel> FindPath(int id, InventLocationViewModel currentLocation)
{
    if (currentLocation.Id == id)
    {
        return new List<InventLocationViewModel> {currentLocation};
    }

    foreach (var child in currentLocation.ChildInventLocations)
    {
        var result = FindPath(id, child);
        if (result != null)
        {
            result.Add(currentLocation);
            return result;
        }
    }
    return null;
}