using System;

namespace BaiTap4

{

    class Program

    {

        static void NhapMang(out int[] a)

        {

            Console.Write("n = ");

            int n = int.Parse(Console.ReadLine());

            a = new int[n];

            for (int i = 0; i < n; i++)

            {

                Console.Write($"a[{i}] = ");

                a[i] = int.Parse(Console.ReadLine());

            }

        }

        static void XuatMang(int[] a)

        {

            Console.Write("Gia tri cua mang la: ");

            for (int i = 0; i < a.Length; i++)

            {

                Console.Write(a[i] + " ");

            }

            Console.WriteLine();

        }

        static void InterchangeSort(int[] a)

        {

            for (int i = 0; i < a.Length - 1; i++)

            {

                for (int j = i + 1; j < a.Length; j++)

                {

                    if (a[i] > a[j])

                    {

                        int temp = a[i];

                        a[i] = a[j];

                        a[j] = temp;

                    }

                }

            }

        }

        static void DemPhanTu(int[] a)

        {

            InterchangeSort(a);

            int count = 1;

            for(int i = 1; i < a.Length; i++)

            {

                if(a[i] != a[i - 1])

                {

                    count++;

                }

            }

            Console.WriteLine($"So phan tu khac nhau trong mang la: {count}");

        }

        static void Main(string[] args)

        {

            int[] a;

            NhapMang(out a);

            XuatMang(a);

            DemPhanTu(a);

            Console.ReadKey();

        }

    }

}

​