using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace bai_1

{

internal class Program

{

public struct SoNguyen

{

public int n;

public SoNguyen Nhap()

{

Console.Write("Nhap n: ");

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

return this;

}

public SoNguyen SetValue (int n)

{

this.n = n;

return this;

}

public void Xuat()

{

Console.Write($"n: {n}");

}

public SoNguyen Cong (SoNguyen b)

{

return new SoNguyen().SetValue(n + b.n);

}

public SoNguyen Tru(SoNguyen b)

{

return new SoNguyen().SetValue(n - b.n);

}

public SoNguyen Nhan(SoNguyen b)

{

return new SoNguyen().SetValue(n * b.n);

}

public SoNguyen Chia(SoNguyen b)

{

if(b.n == 0)

{

throw new Exception("Khong the chia cho khong");

}

return new SoNguyen().SetValue(n / b.n);

}

public static void timGTLNVaTinhTb(SoNguyen[] ds)

{

var gtln = ds.Max(x => x.n);

Console.WriteLine("Gia tri lon nhat: " + gtln);

var tb = ds.Average(x => x.n);

Console.WriteLine("Gia tri trung binh: " + tb);

}

public static SoNguyen[] taoDanhSachSoNguyen(int lenght)

{

SoNguyen[] array = new SoNguyen[lenght];

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

{

Console.WriteLine("Nhap so nguyen " + (i + 1));

array[i] = new SoNguyen().Nhap();

}

return array;

}

public static void inDanhSach(SoNguyen[] ds)

{

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

{

Console.WriteLine("So nguyen thu " + (i + 1) + ": " + ds[i].n);

}

}

}

static void Main(string[] args)

{

Console.OutputEncoding = Encoding.UTF8;

nhapLai:

Console.Write("Nhap vao so luong so nguyen: ");

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

if(n < 0)

{

Console.WriteLine("So luong khong duoc phep am");

goto nhapLai;

}

var ds = SoNguyen.taoDanhSachSoNguyen(n);

SoNguyen.inDanhSach(ds);

var soNguyen1 = new SoNguyen().SetValue(4);

var soNguyen2 = new SoNguyen().SetValue(5);

Console.WriteLine($"Cho a = {soNguyen1.n}, b = {soNguyen2.n}");

var cong = soNguyen1.Cong(soNguyen2);

Console.WriteLine("a + b = " + cong.n);

var tru = soNguyen1.Tru(soNguyen2);

Console.WriteLine("a - b = " + tru.n);

var nhan = soNguyen1.Nhan(soNguyen2);

Console.WriteLine("a * b = " + nhan.n);

var chia = soNguyen1.Chia(soNguyen2);

Console.WriteLine("a / b = " + chia.n + " (chi lay phan nguyen)");

SoNguyen.timGTLNVaTinhTb(ds);

Console.ReadKey();

}

}

}

using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace bai_2

{

internal class Program

{

public struct HangHoa

{

public int id;

public string tenHang;

public string loaiHang;

public int soLuong;

public int donGia;

public HangHoa Nhap()

{

Console.Write("Id: ");

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

Console.Write("Ten hang: ");

tenHang = Console.ReadLine();

nhapLoaiHang:

Console.Write("Loai hang (Tivi, Dien thoai hoac Xe may): ");

loaiHang = Console.ReadLine().Trim().ToLower();

if (loaiHang != "tivi" && loaiHang != "dien thoai" && loaiHang != "xe may")

{

Console.WriteLine("Loai mat hang khong hop le !");

goto nhapLoaiHang;

}

nhapSoLuong:

Console.Write("So luong: ");

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

if (soLuong < 0)

{

Console.WriteLine("So luong khong duoc phep am");

goto nhapSoLuong;

}

nhapDonGia:

Console.Write("Don gia: ");

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

if (donGia < 0)

{

Console.WriteLine("Don gia khong duoc phep am");

goto nhapDonGia;

}

return this;

}

public void Xuat()

{

Console.WriteLine($"id: {id}");

Console.WriteLine($"Ten hang: {tenHang}");

Console.WriteLine($"Loai hang: {loaiHang}");

Console.WriteLine($"So luong: {soLuong}");

Console.WriteLine($"Don gia: {donGia}");

}

public static void Xuat(HangHoa[] ds)

{

int i = 1;

foreach(var item in ds)

{

Console.WriteLine("Hang hoa thu " + i++);

item.Xuat();

}

}

public string pack (string sep = ";")

{

return string.Join(sep, new string[] {id.ToString(), tenHang, loaiHang, soLuong.ToString(), donGia.ToString()});

}

public static HangHoa[] taoDanhSachHangHoa(int lenght)

{

HangHoa[] array = new HangHoa[lenght];

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

{

Console.WriteLine("Nhap thong tin hang hoa thu " + (i + 1));

array[i] = new HangHoa().Nhap();

}

return array;

}

public static long tongGiaTriXeMay(HangHoa[] ds)

{

long sum = 0;

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

{

if(ds[i].loaiHang == "xe may")

{

sum += ds[i].soLuong * ds[i].donGia;

}

}

return sum;

}

public static HangHoa[] sapXepTheoSoLuong (HangHoa[] ds)

{

return ds.OrderBy(item => item.soLuong).ToArray();

}

public static HangHoa[] locMatHangSapHet(HangHoa[] ds)

{

return ds.Where(item => item.soLuong <= 5).ToArray();

}

public static void ghiTep(string duongDan, HangHoa[] ds)

{

var csv = ds.Select(item => item.pack()).ToArray();

if(File.Exists(duongDan))

{

File.Delete(duongDan );

}

File.WriteAllLines(duongDan, csv);

Console.WriteLine("Ghi thanh cong vao " + duongDan);

}

}

static void Main(string[] args)

{

Console.OutputEncoding = Encoding.UTF8;

nhapLai:

Console.Write("Nhap vao so luong hang hoa: ");

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

if (n < 0)

{

Console.WriteLine("So luong khong duoc phep am");

goto nhapLai;

}

var ds = HangHoa.taoDanhSachHangHoa (n);

HangHoa.Xuat(ds);

Console.WriteLine($"Tong gia tri mat hang thuoc loai hang Xe may: " + HangHoa.tongGiaTriXeMay( ds));

ds = HangHoa.sapXepTheoSoLuong(ds);

Console.WriteLine("Danh sach duoc sap xep theo so luong");

HangHoa.Xuat(ds);

Console.WriteLine("Danh sach hang hoa sap het");

var dsSaphet = HangHoa.locMatHangSapHet(ds);

HangHoa.Xuat(dsSaphet);

Console.Write("Nhap vao duong dan: ");

string duongDan = Console.ReadLine();

duongDan += duongDan.EndsWith(@"\") ? "DSTV.txt" : @"\DSTV.txt";

var dsGhi = ds.Where(item => item.loaiHang.ToLower() == "tivi");

HangHoa.ghiTep(duongDan, ds);

Console.ReadKey();

}

}

}