using System.Globalization;
using System.Net.NetworkInformation;
using System.Text;

class Progarm
{
    static void Main()
    {
        // Greet();
        // See https://aka.ms/new-console-template for more information
        // 1. Hello World
        Console.WriteLine("Hello, World!");

        // Shortcuts Ctrl+. | Ctrl+r,r | cw \t\t | Ctrl+k,d | Ctrl+k,c | Ctrl+k,u
        // 2. Primitive data types, variables, literals
        byte myByte1 = 1;
        byte myByte2 = 7;

        sbyte mySByte1 = -1;

        Console.WriteLine(myByte1 + myByte2);


        // I. Types have: name (e.g. int), size, default value
        // II. Variables have: name (A-Za-z_0-9 all utf-8, can't start with 0-9, can't be a keyword), type, value
        // built-in types:  
        //2.1. integer (default = 0)
        byte myByte = 23; // unsigned 8-bis (0 to 255) default = 0
        sbyte mySByte = -128; // signed 8-bit (-128 to 127) default = 0

        short myShort = -1000; // signed 16-bit (-32,768 to 32,767) default = 0
        ushort myUshort = 2000;  // unsigned 16-bit (0 to 65,535) default = 0

        int myVar = 4; // signed 32-bit (-2,147,483,648 to 2,147,483,647)
        int myVar2 = 5; // signed 32-bit (-2,147,483,648 to 2,147,483,647)
        uint myUint = 12000U; // unsigned 32-bit (0 to 4, 294, 967, 295)

        int sum = myVar + myVar2; // signed 32-bit (-2,147,483,648 to 2,147,483,647)

        sum = 0xA8F1; // hexadecimal literal
        sum = 0XA8F1; // hexadecimal literal

        // Greet();

        long myLong = 42432L;// signed 64-bit (-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807)
        ulong myUlong = 23423423U; // unsigned 64-bit (0 to 18,446,744,073,709,551,615)
        ulong maxIntValue = UInt64.MaxValue;
        Console.WriteLine(maxIntValue); // 18446744073709551615

        // 2.2. Real (default 0.0 for F/f D/d M/m)
        float myFloat = 4.566F; // signed 32-bit (±1.5e-45 to ±3.4e38) up to 7 symbols/digits
        myFloat = 67.8E35f; // litteral with "E/e"

        double myDouble = 34.56d; // signed 64-bit (±5.0e-324 to ±1.7e+308) up to 15-16 symbols/digits
        myDouble = -3.4e-10;

        decimal myDecimal = 23.45M; // signed 128-bit (±1.0e-28 to ±7.9e28) precission 28-29 symbols/digits, closest to 0 ±1.0e-28, decimal floating-point arithmetic


        // Declare some variables
        float floatPI = 3.141592653589793238f;
        double doublePI = 3.141592653589793238;
        decimal decimalPI = 3.14159265358979323846m;

        Console.WriteLine("Float PI is: " + floatPI); // Float PI is: 3.141593 only 7 digits
        Console.WriteLine("Double PI is: " + doublePI); // Double PI is: 3.14159265358979  16 digits
        Console.WriteLine(decimalPI); // 3.14159265358979323846

        // 2.3. Char
        char myFirstLetter = 'S';
        Console.WriteLine((int)myFirstLetter);

        char symbol = (char)78;
        Console.WriteLine(symbol);
        char myChar = '\u0065';
        Console.WriteLine(myChar);

        myChar = '\uffff';
        Console.WriteLine(myChar);

        myChar = '\'';

        // escaping
        char myEscape = '\n'; // \n \t \r \' \\ \" \uXXXX

        // 2.4. String (default null) Reference, value in the heap. String.Compare(string1, string2) > 0 if they have to switch
        string myName = "Stoyan Cheresharov";

        // 2.5. Bool (default false)
        bool myBool = true; // false | true


        Object myObject = 2;
        myObject = "Stoyan";


        // 3. 
        int a = 5;
        int b = 4;
        Console.WriteLine(a + b); // 9
        Console.WriteLine(a + b++); // 9
        Console.WriteLine(a + b); // 10
        Console.WriteLine(a + (++b)); // 11
        Console.WriteLine(a + b); // 11
        Console.WriteLine(14 / a); // 2
        Console.WriteLine(14 % a); // 4

        // 3.1. Arithmetic operators 
        a = 11;
        b = 2;
        // Arithmetic operators
        Console.WriteLine(a + b);
        Console.WriteLine(a - b);
        Console.WriteLine(a / b);
        Console.WriteLine(a * b);
        Console.WriteLine(a++);
        Console.WriteLine(a);
        Console.WriteLine(++a);
        Console.WriteLine(a % b);
        Console.WriteLine(--a);
        Console.WriteLine(a--);

        //3.2. For comparison
        Console.WriteLine(a > b);
        Console.WriteLine(a < b);
        Console.WriteLine(a >= b);
        Console.WriteLine(a <= b);
        Console.WriteLine(a == b);
        Console.WriteLine(a != b);

        //3.3. Logical
        bool x = true;
        bool y = false;

        Console.WriteLine(x && y);
        Console.WriteLine(x || y);
        Console.WriteLine(x ^ y);
        Console.WriteLine(!x);

        //&&
        //x   y   z
        //0   0   0
        //1   0   0
        //0   1   0
        //1   1   1

        // ||
        //x   y   z
        //0   0   0
        //1   0   1
        //0   1   1
        //1   1   1

        // ^
        //x   y   z
        //0   0   0
        //1   0   1
        //0   1   1
        //1   1   0

        // !
        //x z
        //0 1
        //1 0 

        ////3.4. for asignments
        //a += 3; // a = a + 3;

        ////3.5. Bitwise operators
        //Console.WriteLine(1 << 1);
        //Console.WriteLine(2 >> 1);
        //Console.WriteLine(1 | 2);
        //Console.WriteLine(1 & 2);
        //Console.WriteLine(1 ^ 3);// 2


        //// 3.6. trinary
        //int c = (a > b) ? a : b;

        //if (a > b)
        //{
        //    c = a;
        //}
        //else
        //{
        //    c = b;
        //}

        ////int? a1 = null;
        ////int? b1 = 6;
        //// a1 = null;
        ////int? z = a1 ?? b1;


        /*
                // 4. Console
                Console.OutputEncoding = Encoding.UTF8;
                Thread.CurrentThread.CurrentCulture = CultureInfo.GetCultureInfo("de-DE");

                Console.Write("Stoyan ");
                Console.Write("Cheresharov");
                Console.WriteLine("My name is Desi. I am {0} years old. my favorite number is {1}", 10, 3);
                Console.WriteLine("{0,10:C2} I will continue", 1234);

                // Formatting Numbers
                // Standard Formatting Symbols C, D, E, F, N, P, X
                Console.WriteLine("{0:C2}", 123.456); //Output: 123,46 лв.
                Console.WriteLine("{0:D6}", -1234); //Output: -001234
                Console.WriteLine("{0:E2}", 123); //Output: 1,23Е+002
                Console.WriteLine("{0:F2}", -123.456); //Output: -123,46
                Console.WriteLine("{0:N2}", 1234567.8); //Output: 1 234 567,80
                Console.WriteLine("{0:P}", 0.456); //Output: 45,60 %
                Console.WriteLine("{0:X}", 254); //Output: FE

                // Custom Formatting Symbols 0000, ###, %, E0 Е+0 Е-0
                Console.WriteLine("{0:0.00}", 1); //Output: 1,00
                Console.WriteLine("{0:#.##}", 0.234); //Output: ,23
                Console.WriteLine("{0:#####}", 12345.67); //Output: 12346
                Console.WriteLine("{0:(0#) ### ## ##}", 29342525); //Output: (02) 934 25 25
                Console.WriteLine("{0:%##}", 0.234);//Output: %23

                //Console.ForegroundColor = ConsoleColor.DarkYellow;
                //Console.BackgroundColor = ConsoleColor.DarkBlue;
                Console.Clear();
                // Standard Formatting Symbols for DateTime
                DateTime d = DateTime.Now;

                Console.WriteLine("{0:d}", d); // d D

                //Console.SetCursorPosition(5, 10); // left top
                Console.WriteLine("Това е кирилица: ☺");

                // char unicorn = '\u1F984'; ???

                Console.Write("Please enter your age: ");

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

                string name = "Stoyan";

                char firstLetter = name[0];

                int number = 312321;
                string numberString = number.ToString();
                Console.WriteLine(numberString[1]);

                // 5. Conditional Logic
                int secondNumber = 3;
                int firstNumber = 2;
                if (secondNumber > firstNumber)
                {
                    Console.WriteLine("secondNumber > firstNumber");
                }

                if (true)
                {
                    Console.WriteLine("secondNumber > firstNumber");
                }
                else
                {
                    Console.WriteLine("secondNumber > firstNumber");
                }

                int myAge = 12;

                if (myAge < 3)
                {
                    Console.WriteLine("You are a baby!");
                }
                else if (3 <= myAge && myAge < 12)
                {
                    Console.WriteLine("You are a kid!");
                }
                else if (12 <= myAge && myAge < 18)
                {
                    Console.WriteLine("You are a teenager!");
                }
                else if (18 <= myAge && myAge < 30)
                {
                    Console.WriteLine("You are in your golden age!");
                }
                else
                {
                    Console.WriteLine("You are an adult");
                }


                char firtsLetter = 'S';
                switch (firtsLetter)
                {
                    case 'A':
                    case 'S':
                        Console.WriteLine("Your first letter tells me you are a lucky man!");
                        break;
                    case 'V':
                        Console.WriteLine("You are victorious!");
                        break;
                    default:
                        Console.WriteLine("I don't know?");
                        break;
                }

                // 6. loops
                int i = 0;
                while (i < 100)
                {
                    Console.WriteLine(i);
                    i++;
                }

                int number1 = 0;
                do
                {
                    Console.Write("Please, enter a number between 0 and 10:");
                    number1 = int.Parse(Console.ReadLine());

                } while (number1 < 0 || number1 > 10);

                for (i = 0; i < 100; i++)
                {
                    Console.WriteLine(i);
                }

                int[] myArray = { 1, 2, 3,};
                foreach (var item in myArray)
                {
                    Console.WriteLine(item);
                }

                Console.Write("Please, enter a character: ");
                int myChar1 = Console.Read();
                Console.WriteLine(myChar1);

                // int lucky = 1235;
                int a1, a2, a3, a4;

                for (int lucky = 0; lucky <= 9999; lucky++)
                {
                    a1 = lucky / 1000;
                    a2 = (lucky / 100) % 10;
                    a3 = (lucky / 10) % 10;
                    a4 = lucky % 10;

                    if (a1 + a2 == a3 + a4)
                    {
                        Console.WriteLine(lucky);
                    }
                }
        */

        Console.Clear();
        // 7.
        int[] ints = { 212, 22, 3, 4 };
        ints[0] = 34;
        Console.WriteLine(ints[0]);

        // 7.1.
        int[] ints1 = new int[3];
        ints1[1] = 4;

        // 7.2.
        int[] ints2 = new int[3] { 32, 45, 67 };

        int lastElement = ints2[ints2.Length - 1];

        for (int i = 0; i < ints2.Length; i++)
        {
            Console.WriteLine(ints2[i]);
        }

        int[,] matrix =
        {
            {32, 34, 45 },
            { 56, 54, 34},
            { 543, 34, 43}
        };

        int[][] jagged = {
            new int[] { 32, 45, 67},
            new int[] {6456, 5435, 54345, 545}
        };

        Console.WriteLine(jagged[1][1]);

        List<int> myList = new List<int>();
        myList.Add(23);

        Dictionary<string, string> myDictionary = new Dictionary<string, string>();

        myDictionary.Add("щастлив", "happy");

        Console.WriteLine(myDictionary["щастлив"]);

        var tugay = "String";

        // var myInput = int.Parse(Console.ReadLine());

        foreach (var item in myList)
        {
            Console.WriteLine(item);
        }

        string[] places = { "София", "пловдив" };

        int counter = 0;
        for (int i = 0; i < places.Length; i++)
        {
            if (char.IsUpper(places[i][0]))
            {
                Console.WriteLine(places[i]);
                counter++;
            }
        }

        Console.WriteLine("The cities with capital Letter are {0}", counter);

        Console.WriteLine("2093 to BIN {0}.", Convert.ToString(2093, 2));
        Console.WriteLine("2093 to OCT {0}.", Convert.ToString(2093, 8));
        Console.WriteLine("2093 to HEX {0}.", Convert.ToString(2093, 16));
        Console.WriteLine("2093 In a number system with base/radix = 5 {0}.",
            Convert.ToString(2093, 2));

        Console.WriteLine();

        for (int i = ints2.Length - 1; i >= 0; i--)
        {
            Console.WriteLine(ints2[i]);
        }

        // 9. Methods
        Greet(null, 1,2,23);

        //Greet(ages: 1, 23, 4, name : "Viktor" );

        int[] myArray = { 1231, 432432, 4234 };

        Console.WriteLine(GetAverage(myArray));


        Console.WriteLine(FactorialIter(10));

        // 0! = 1
        // n! = (n-1)! * n

        // 3! = 1 * 2 * 3 = 6
        Console.WriteLine(FactorialRecur(10));

        //
        String[] students = new String[3];
        // zad 371
        // a
        InputStudentsNames(students);

        // b
        OutputStudents(students);

        // c
        String[] femailNames = GetFemaleNames(students);
        OutputStudents(femailNames);




        //double calc = 0;
        //for (int x = 0; x < 169; x++)
        //{
        //    for (int y = 0; y < 256; y++)
        //    {
        //        calc = Math.Pow(x, 2) / 169 + Math.Pow(y, 2) / 256;
        //        if (calc < 1)
        //        {
        //            Console.WriteLine($"The point with coordinates x = {x} y = {y} is inside the elipse");
        //        }
        //    }
        //}

        //Console.WriteLine(DateTime.Now);

        //int x1 = 0, y1 = 0;

        //while (true)
        //{
        //    Console.Clear();
        //    Console.SetCursorPosition(x1, y1);
        //    Console.WriteLine(DateTime.Now);
        //    Thread.Sleep(10);
        //    x1++;
        //    y1++;
        //}


        // 8.

        // IV
        //VI

        //44(10)

        //4 * 10 ^ 1 + 4 * 10 ^ 0 = 40 + 4

        //44(8)

        //4 * 8 ^ 1 + 4 * 8 ^ 0 = 32 + 4 = 36

        //44(5)
        //4 * 5 ^ 1 + 4 * 5 ^ 0 = 20 + 4 = 24

        //44

        //44 : 2 = 22 | 0
        //22 : 2 = 11 | 0
        //11 : 2 = 5 | 1
        //5 : 2 = 2 | 1
        //2 : 2 = 1 | 0
        //            1

        //101100(2) = 44(10)


        //0010 1100

        //2C

        //8421

        //101 100
        //5    4

        //54()

        //23.45

        //23 : 2 = 11 | 1
        //11 : 2 = 5 | 1
        //5 : 2 = 2 | 1
        //2 : 2 = 1 | 0

        //        1

        //10111.011

        //1.0111011 * 2 ^ 4

        //.45 * 2 = 0.9 | 0
        //0.9 * 2 = 0.8 | 1
        //0.8 * 2 = 0.6 | 1

        //123.56 => 1,23.56 * 10 ^ 2


        //number = 346
        //(r ^ n - 1) - number

        //(10 ^ 3 - 1) - 346 =
        //999
        //-
        //346
        //---- -
        //653

        //9999999999
        //-
        //4332423532
        //----------------
        //5667...


        //1111111111111
        //-
        //1010101111111
        //------------------
        //0101010000000

        //(r ^ n - 1) - number
        //(r ^ n) - number


        //7 - 3 = 4

        //7 + 7 = 1 | 4






        /*

        // ------ in a nutshell -----

        //a += 3; // a = a + 3;

        //// essentials
        //// 4.
        //Console.WriteLine();
        //string name = Console.ReadLine();
        //double n = double.Parse(Console.ReadLine());

        //// 5. Conditional logic
        //// 5.1.
        //if (a > 5)
        //{
        //    Console.WriteLine("a > 5");
        //}

        //if (a > 5)
        //{
        //    Console.WriteLine("a > 5");
        //}
        //else
        //{
        //    Console.WriteLine("a < 5");
        //}

        //Console.WriteLine("Please enter your age: ");
        //int age = int.Parse(Console.ReadLine());
        //if (age > 0 && age <= 3)
        //{
        //    Console.WriteLine("You are a baby");
        //}
        //else if (age > 3 && age <= 12)
        //{
        //    Console.WriteLine("You are a kid");
        //}
        //else if (age > 12 && age <= 18)
        //{
        //    Console.WriteLine("You are a teenager");
        //}
        //else
        //{
        //    Console.WriteLine("You are an adult");
        //}


        //char firstLetter = Char.Parse(Console.ReadLine());
        //switch (firstLetter)
        //{
        //    case 'A':
        //    case 'N':
        //        Console.WriteLine("Maybe your name is Nilyay");
        //        break;
        //    default:
        //        Console.WriteLine("I don't know");
        //        break;
        //}


        //// 6. Loops

        //int i = 0;
        //while (i < 100)
        //{
        //    Console.WriteLine(i);
        //    i++;
        //}


        //do
        //{
        //    Console.WriteLine("Please enter your age: ");
        //    age = int.Parse(Console.ReadLine());
        //} while (age < 0 && age > 120);



        //for (i = 0; i < 100; i++)
        //{
        //    Console.WriteLine(i);
        //}
        Greet("Nilyay");
        int[] ages = new int[10];
        ages[0] = 18;
        ages[5] = 17;

        foreach (int item in ages)
        {
            Console.WriteLine(item);
        }

        Greet("Magi");


        int number = 5698;
        int a1 = number / 1000;
        int a2 = (number / 100) % 10;
        int a3 = (number / 10) % 10;
        int a4 = number % 10;

        Console.WriteLine("The number in reverse is {0}{1}{2}{3}", a4, a3, a2, a1);
    }

    static void Greet(string name = "Megan")
    {
        Console.WriteLine("Hello" + name);
    }

    static int CalculateSum(int a, int b)
    {
        return a + b;
    }

    */

    }

    static void Greet(String name = "Viktor", params int[] ages)
    {
        Console.WriteLine($"Hello {name}");
        foreach (var item in ages)
        {
            Console.WriteLine(item);
        }
    } 

    static double GetAverage(int[] n)
    {
        double average = 0;
        int sum = 0;
        foreach (var item in n)
        {
            sum += item;
        }
        if (n.Length != 0) average = sum / n.Length;
        return average;
    }

    static int FactorialIter(int n)
    {
        int mul = 1;
        for (int i = 1; i <= n; i++)
        {
            mul *= i;
        }
        return mul;
    }

    // 0! = 1
    // n! = (n-1)! * n
    static int FactorialRecur(int n)
    {
        if (n == 0) return 1;
        return FactorialRecur(n - 1) * n;
    }

    static void InputStudentsNames(String[] names)
    {
        for (int i = 0; i < names.Length; i++)
        {
            Console.Write("Please, enter the name (first, middle, family) of {0}:", i);
            names[i] = Console.ReadLine();
        }
    }

    static void OutputStudents(String[] students)
    {
        for (int i = 0; i < students.Length; i++)
        {
            Console.WriteLine("Student number {0} = {1}", i, students[i]);
        }
    }

    static String[] GetFemaleNames(String[] students)
    {
        String[] femaleNames = new String[students.Length];
        int counter = 0;
        for (int i = 0; i < students.Length; i++)
        {
            if (students[i][students.Length - 1] == 'а')
            {
                femaleNames[counter] = students[i];
                counter++;
            }
        }
        return femaleNames;
    }


}