BangumiRenamer/EpisodeGroup.cs

namespace ConsoleApp1;

public class Node
{
    public string spot;
    public List<Node> son;
    public string session;
    public string title;
    public bool isOverride;
}

public class EpisodeGroup
{
    private Node _root;
    
    public readonly List<EpisodeInfo> episodes = new List<EpisodeInfo>();
    
    private Node FindOrCreateShow(Node node, string spot)
    {
        if (node.son == null)
        {
            node.son = new List<Node>();
        }

        Node target = null;
        foreach (var son in node.son)
        {
            if (son.spot == spot)
            {
                target = son;
                break;
            }
        }
        if (target == null)
        {
            target = new Node
            {
                spot = spot,
                isOverride = false
            };
            node.son.Add(target);
        }
        return target;
    }
    
    private void Add(EpisodeInfo episode)
    {
        if (_root == null)
        {
            _root = new Node
            {
                spot = "",
                isOverride = false
            };
        }

        var curr = _root;
        var spots = episode.path.Split('/');
        foreach (var spot in spots)
        {
            curr = FindOrCreateShow(curr, spot);
        }
        curr.session = episode.session;
        curr.title = episode.name;
        curr.isOverride = true;
    }
    
    public void Run()
    {
        _root = null;
        foreach (var episode in episodes)
        {
            Add(episode);
        }

        DoRun(_root);

        foreach (var episode in episodes)
        {
            var curr = _root;
            var spots = episode.path.Split('/');
            foreach (var spot in spots)
            {
                curr = FindOrCreateShow(curr, spot);
                if (curr.isOverride)
                {
                    episode.name = curr.title;
                    episode.session = curr.session;
                    break;
                }
            }
        }
    }

    private void DoRun(Node node)
    {
        if (node == null) return;
        if (node.son == null) return;
        foreach (var son in node.son)
        {
            DoRun(son);
        }
        var query = (from son in node.son
            where son.isOverride
                select son).GroupBy(node => (node.title, node.session));
        foreach (var group in query)
        {
            if (group.Count() * 2 > node.son.Count)
            {
                node.isOverride = true;
                (node.title, node.session) = group.Key;
            }
        }
    }
}