using System;

using System.Linq;

using System.Collections.Generic;

public class Program

{   

    /// <summary>

    /// Your task is to implement the 4 functions in this class.

    /// Only make changes to THIS class!

    /// Once you have finished use the Share button above to copy the link and send us your implementation.

    /// You can add extra methods or classes you like, but don't alter the signatures of the existing methods.  

    /// The project is runnable, so you can run it.

    /// You can use any C# code you like: .net framework functions, base classes etc

    /// Feel free to use a popular websearch engine to research your answers or to look for sample code.  BUT...

    /// *** IMPORTANT : If you do find something via Google that you end up using, write the URL in a comment. ***

    /// </summary>

    public static class Implementation

    {

        //a count of the number of animals who have a clinical code with CodeID == 1

        public static int CountOfCode1(List<Animal> animals)

        {

            return animals.Count(a => a.Codes.Any(c => c.CodeID == 1));

        }

​

        //return a new list with only unique codes (codes are considered duplicates if they have the same value for their CodeID property)

        public static List<ClinicalCode> ReturnUniqueCodes(List<ClinicalCode> list) {

            // If CodeID property is same for 2 items - first item is considered as the exact item

            // Implemented this function since I found it in the exercise even though this impl is not required for the code to work

            return list.GroupBy(l => l.CodeID).Select(g=>g.FirstOrDefault()).ToList();

        }

​

        //list the animalIDs which are contained in BOTH listA AND listB

        public static List<int> AnimalsInBothLists(List<Animal> listA, List<Animal> listB) 

        {

            var listAAnimals = listA.Select(a => a.AnimalID);

            var result = listB.Where(a => listAAnimals.Contains(a.AnimalID));

            return result.Select(a => a.AnimalID).ToList();

        }

​

        //list the animalIDs in listA that are not in listB

        public static List<int> AnimalsOnlyInA(List<Animal> listA, List<Animal> listB)

        {

            var listBAnimals = listB.Select(a => a.AnimalID);

            var result = listA.Where(a => !listBAnimals.Contains(a.AnimalID));

            return result.Select(a => a.AnimalID).ToList();

        }

​

        //a count of the number of animals who have BOTH : 

        //  a CLINICAL CODE with CodeID == 1 

        //  AND a CLINICAL CODE with CodeID == 2 

        public static int CountOfCode1And2(List<Animal> animals)

        {

            var withCodeIdOne = animals.Where(a=>a.Codes.Any(c => c.CodeID == 1));

            var withCodeIdTwo = animals.Where(a=>a.Codes.Any(c => c.CodeID == 2));

            var withBoth = withCodeIdOne.Intersect(withCodeIdTwo);

            return withBoth.Count();

        }

​

    }

    public class ClinicalCode

    {        

        /// <summary>

        /// Unique ID of the code

        /// </summary>

        public int CodeID { get;  set; }

        public string CodeName { get;  set; }

    }

    public class Animal

    {

        /// <summary>

        /// Unique Id of the animal

        /// </summary>

        public int AnimalID { get;  set; }

​

        /// <summary>

        /// Clinical codes that the animal has been diagnosed with

        /// </summary>

        public List<ClinicalCode> Codes { get;  set; }

​

        public override bool Equals(object obj)

        {

            var other = obj as Animal;

            if (other == null)

                return false;

            return this.AnimalID == other.AnimalID;

        }

​

        public override int GetHashCode()

        {

            return AnimalID;

        }

    }

    public static void Main(string[] args)

    {

        //Feel free to run this code, but don't change it

        Implementation.CountOfCode1(DataSource.GetSomeData().ToList());

        Implementation.CountOfCode1And2(DataSource.GetSomeData().ToList());

        Implementation.AnimalsInBothLists(DataSource.GetSomeData().ToList(), DataSource.GetSomeData().ToList());

        Implementation.AnimalsOnlyInA(DataSource.GetSomeData().ToList(), DataSource.GetSomeData().ToList());

    }

    public static class DataSource {

        public static Random rnd = new Random();

​

        /// <summary>

        /// This generates some random dummy data to for you to work with

        /// </summary>

        /// <returns></returns>

        public static IEnumerable<Animal> GetSomeData()

        {

            var max = rnd.Next(300, 400); //a random number of patients

            return Enumerable.Range(1, max).Select(animalId => {

​

                //foreach animal create some random codes

                var codes = Enumerable.Range(1, 11).Select(codeId => {

                    var clinicalCodeId = rnd.Next(1, 5);

                    return new ClinicalCode

                    {

                        CodeID = clinicalCodeId,

                        CodeName = "The name of the diagnosis"

                    };

                });

​

                return new Animal {

                    AnimalID = animalId,

                    Codes = codes.ToList()

                };

            });

        }

    }

}