DictionaryHome

using System;
using System.Collections.Generic;
using System.Linq;

namespace _20._04._21
{
    class Program
    {
        static void Main(string[] args)
        {
            var groups = new Dictionary<string, string>();

            groups.Add("Group1", "Song1");
            groups.Add("Group2", "Song2");
            groups.Add("Group3", "Song3");
            groups.Add("Group4", "Song4");
            groups.Add("Group5", "Song5");

            while (true)
            {
                Console.WriteLine($"Chose 1 to search by group or 2 by song");
                int num = int.Parse(Console.ReadLine());
                var input = Console.ReadLine();

                if (num == 1)
                {
                    if (groups.ContainsKey(input))
                    {
                        Console.WriteLine($"Song is: {groups[input]}");
                    }
                    else
                        Console.WriteLine($"Group did not found!");
                }
                else
                {
                    if (groups.ContainsValue(input))
                    {
                        Console.WriteLine($"Group is: {groups.First(x => x.Value == input).Key}");
                    }
                    else
                        Console.WriteLine($"Song did not found!");
                }
            }
        }
    }
}