using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

​

namespace ConsoleApp3

{

    class Program

    {

        static void Main(string[] args)

        {

​

            //2 - Write a program and ask the user to enter a few numbers separated by a hyphen.If the user simply presses Enter, 

            //    without supplying an input, exit immediately; otherwise, check to see if there are duplicates. 

            //    If so, display "Duplicate" on the console.

​

            Console.WriteLine("Enter numbers seperated by a hyphen");

            var firstInput = Console.ReadLine();

​

​

            if (string.IsNullOrEmpty(firstInput))

            {

                Console.WriteLine("No numbers supplied, program shutdown");

            }

            else if (numList.Count() != numList.Distinct().Count())

            {

                Console.WriteLine("Duplicate found!");

            }

            else

            {

                Console.WriteLine("No duplicate found");

            }

​

        }

        public static string duplicate()

        {

            var num = firstInput.Split('-');

            var numstrList = new List<string>();

            numstrList.AddRange(num);

​

            var numList = new List<int>();

            foreach (var n in num)

            {

                int.TryParse(n, out int number);

                numList.Add(number);

            }

        }

    }

}

​