// Online C# Editor for free

// Write, Edit and Run your C# code using C# Online Compiler

​

using System;

using System.Collections.Generic;

​

public interface IEntity<T>

{

    T Id { get; set; }

}

​

public interface INode<TId> : IEntity<TId>

{

    string Name { get; set; }

}

​

public interface ITreeNode<TId, TItem> : INode<TId> 

    where TItem : INode<TId>

{

    List<TItem> Children { get; set; }

    TItem GetValue();

}

​

public record Geolocation : ITreeNode<int, Geolocation>

{

    public int Id { get; set; }

    public string Name { get; set; }

    public List<Geolocation> Children { get; set; } = new();

    public string Type { get; set; }

    public Geolocation GetValue(){

        return (Geolocation) this;

    }

}

​

public record Category : ITreeNode<string, Category>

{

    public string Id { get; set; }

    public string Name { get; set; }

    public List<Category> Children { get; set; } = new();

    public decimal Cost { get; set; }

    public Category GetValue(){

        return (Category) this;

    }

}

​

public class HelloWorld

{

    public static void Main(string[] args)

    {

        List<Category> categories = new()

        {

            new()

            {

                Id = "1",

                Name = "cat 1",

                Cost = 15,

                Children = new List<Category>

                {

                    new()

                    {

                        Id = "2",

                        Name = "cat 2",

                        Cost = 15

                    },

                    new()

                    {

                        Id = "3",

                        Name = "cat 3",

                        Cost = 15

                    }

                }

            },

            new()

            {

                Id = "4",

                Name = "cat 4",

                Cost = 15,

                Children = new List<Category>

                {

                    new()

                    {

                        Id = "5",

                        Name = "cat 5",

                        Cost = 15

                    },

                    new()

                    {

                        Id = "6",

                        Name = "cat 6",

                        Cost = 15

                    }

                }

            }

        };

​

        List<Geolocation> locations = new()

        {

            new()

            {

                Id = 1,

                Name = "cat 1",

                Type = "Country",

                Children = new List<Geolocation>

                {

                    new()

                    {

                        Id = 2,

                        Name = "cat 2",

                        Type = "Country"

                    },

                    new()

                    {

                        Id = 3,

                        Name = "cat 3",

                        Type = "Country"

                    }

                }

            },

            new()

            {

                Id = 4,

                Name = "cat 4",

                Type = "Country",

                Children = new List<Geolocation>

                {

                    new()

                    {

                        Id = 5,

                        Name = "cat 5",

                        Type = "Country"

                    },

                    new()

                    {

                        Id = 6,

                        Name = "cat 6",

                        Type = "Country"

                    }

                }

            }

        };

​

​

        Category category = TreeFinder("5", categories).GetValue();

        Geolocation location = TreeFinder(5, locations).GetValue();

        Console.WriteLine(category);

        Console.WriteLine(location);

    }

​

    public static ITreeNode<TId, TItem> TreeFinder<TId, TItem>(TId id, IEnumerable<TItem> nodes)

        where TItem : class, ITreeNode<TId, TItem>

    {

        if(id.Equals(default)) return null;

        if(nodes == null) return null;

        foreach (ITreeNode<TId, TItem> node in nodes)

        {

            if (node.Id.Equals(id))

                return node;

​

            ITreeNode<TId, TItem> childNode = TreeFinder(id, node.Children);

            if (childNode != null)

                return childNode;

        }

​

        return null;

    }

}