using System using System Collections Generic using System Linq using

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

namespace ConsoleApplication1
{
    class student
    {
        public string first { get; set; }
        public string last { get; set; }
        public int id { get; set; }
        public int[] scores;
        public override string ToString()
        {
            return first  + ' ' + last + ' '+ id;
        }
        
    }
    class Program
    {
        static void Main(string[] args)
        {
            student[] stud = new student[4] { new student { first = "Garaev", last = "raf", id = 111, scores = new int[] { 5, 5, 5, 4 } },
                                              new student { first = "ivanov", last = "ivan", id = 112, scores = new int[] { 4, 5, 3, 4 } },
                                              new student { first = "igor", last = "igor", id = 113, scores = new int[] { 4, 5, 3, 5 } },
                                              new student { first = "vanya", last = "vanya", id = 114, scores = new int[] { 4, 2, 3, 4 } },   };
            foreach (student s in stud)
            {
                Console.WriteLine(s);
            }
           // student r = new student;
            Console.WriteLine();
            Console.WriteLine("Первый запрос");
            IEnumerable<student> Query1 =

                from r in stud
                where r.id > 111
                select r;
                Console.WriteLine();
            foreach (student s in Query1)
            {
               Console.WriteLine(s);
            }
            Console.WriteLine();
            Console.WriteLine("Второй запрос");
            IEnumerable<string> Query2 =

                from r in stud
                where r.id > 111
                select r.last;
            Console.WriteLine();
            foreach (string s in Query2)
            {
                Console.WriteLine(s);
            }
            Console.WriteLine();
            Console.WriteLine("Третий запрос");
            IEnumerable<int> Query3 =

                from r in stud
                where r.id > 111
                select r.scores[0];
            Console.WriteLine();
            foreach (int s in Query3)
            {
                Console.WriteLine(s);
            }
            Console.WriteLine();
            Console.WriteLine("Четвёртый запрос");
            IEnumerable<double> Query4 =

                from r in stud
                where r.id > 111
                select r.scores.Average();
            Console.WriteLine();
            foreach (double s in Query4)
            {
                Console.WriteLine(s);
            }
            Console.WriteLine();
            Console.WriteLine("Пятый запрос");
            var Query5 =

                from r in stud
                where r.id > 111
                select new { r.first, r.last };
            Console.WriteLine();
            foreach (var s in Query5)
            {
                Console.WriteLine(s.first + ' ' + s.last);
            }
            //в мсдн изменить переделать запросы ПРИМЕР
            Console.WriteLine();
            Console.WriteLine("Шестой запрос");
            IEnumerable<student> num1 = stud.Where(r => r.id > 111);
            foreach (student s in num1)
            {
                Console.WriteLine(s);
            }
            Console.WriteLine();
            Console.WriteLine("седьмой запрос");
            IEnumerable<string> num2 = stud.Where(r => r.id > 111).Select(r => r.last);
            foreach (string s in num2)
            {
                Console.WriteLine(s);
            }
            Console.WriteLine();
            Console.WriteLine("Восьмой запрос");
            IEnumerable<int> num3 = stud.Where(r => r.id > 111).Select(r => r.scores[0]);
            foreach (int s in num3)
            {
                Console.WriteLine(s);
            }
            Console.WriteLine();
            Console.WriteLine("Девятый запрос");
            IEnumerable<double> num4 = stud.Where(r => r.id > 111).Select(r =>r.scores.Average());
            foreach (double s in num4)
            {
                Console.WriteLine(s);
            }
            Console.WriteLine();
            Console.WriteLine("десятый запрос");
            var num5 = stud.Where(r => r.id > 111).Select(r => new { r.first, r.last });
            foreach (var s in num5)
            {
                Console.WriteLine(s.first + ' ' + s.last);
            }
            Console.WriteLine("Работает!!");
            
        }
    }
}