IntroC#_loops_arrays_decimal_methods_recursion_2a

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

namespace HelloWorld2a
{
    class Program
    {
        static void Main(string[] args)
        {
            // !!! Use Ctrl + F5 to rub the program in VS
            // F10 - trace the program. Execute step by step without entering the methods
            // F9 - set a break point. F5 reach the breakpoint and use F10 or F11 to execute step by step
            // F11 - trace with entering the methods.
            // F10 ("step over") does not descend any further into the call stack. It moves to the next line of the current function.
            // F11 ("step into") drills down into the function being called.
            // http://visualstudioshortcuts.com/2015/

            // 1. Variables, types, literals
            int age = -128;
            double money = 2.54D;
            char firstLetter = 'S'; // '\u000f';
            bool isMale = true;
           // int 2f1dhgf = 12; ERROR can not start with number
            string name = "Stoyan";
            object myObject = 5;
            // All types:
            // byte (8 bits), sbyte, short, ushort, int (32 bits), uint, long, ulong (64 bits)
            // float (32 bits, 7 digits after the point), double (64 bits, 15-16 digits after), decimal (128 bits)
            // char
            // string
            // bool
            // object
            // literals: uint 0u, ulong 0u, long 0L, float 0.0f, double 0.0d, decimal 0.0m , char '\u0000,
            // 0xaa (base 16), 3.14e+1 = 31.4, can have letter at the end as well 3.14e+1f for float ()
            // Escape: \uXXXX, \', \", \\, \n, \t

            // paradox
            double sum = 0.1 + 0.2;
            Console.WriteLine(sum == 0.3); // False


            Nullable<int> myNUllable = null;
            int? anotherNullable = myNUllable;

            int first = 13;
            int second = 2;
            double result;
            result = first / second; // !!! result is 6. If you want to get the right 6.5 convert the types
            result = (double)first / second; // !!! the right 6.5

            Console.WriteLine(13 / 2); // 6 integer divide by integer gives integer
            Console.WriteLine(13 / 2.0 ); // 6.5 integer divided by double gives double


            DateTime timeNow = DateTime.Now; // // 15.9.2016 г. 13:24:17 ч.
            timeNow = timeNow.AddYears(2);
            Console.WriteLine(timeNow); // 15.9.2018 г. 13:24:17 ч.

            DateTime myDateTime = new DateTime();
            Console.WriteLine(myDateTime); // 1.1.0001 г. 00:00:00 ч.

            // 2. Operators

/*
            byte a = 13;
            byte b = 5;
            // 1.
            Console.WriteLine("{0} + {1} = {2}",a, b, a + b);
            Console.WriteLine("{0} - {1} = {2}", a, b, a - b);
            Console.WriteLine("{0} * {1} = {2}", a, b, a * b);
            Console.WriteLine("{0} / {1} = {2}", a, b, a / b);
            Console.WriteLine("{0} % {1} = {2}", a, b, a % b);
            Console.WriteLine("++{0}  = {1}", a, ++a);

            // 2. comparison
            Console.WriteLine("{0} < {1} = {2}", a, b, a < b);
            Console.WriteLine("{0} > {1} = {2}", a, b, a > b);
            Console.WriteLine("{0} <= {1} = {2}", a, b, a <= b);
            Console.WriteLine("{0} >= {1} = {2}", a, b, a >= b);
            Console.WriteLine("{0} == {1} = {2}", a, b, a == b);
            Console.WriteLine("{0} == {1} = {2}", a, b, a != b);

            // 3. Boolean
            bool c = true;
            bool d = false;

            Console.WriteLine("{0} && {1} = {2}", c, d, c && d);
            Console.WriteLine("{0} || {1} = {2}", c, d, c || d);
            Console.WriteLine("{0} ^ {1} = {2}", c, d, c ^ d);
            Console.WriteLine("!{0} = {1}", c, !c);

            // kdjsfhsdkfjh askjfsdk fdkjh fksjh fkjsd
            // a = 5; // a = a + 5;

            Console.WriteLine("{0} << 1 {1}", 1, 1 << 1);
            Console.WriteLine("{0} >> 1 {1}", 1, 1 >> 1);
            Console.WriteLine("{0} | {1} = {2}", a, b, a | b);
            Console.WriteLine("{0} & {1} = {2}", a, b, a & b);
            Console.WriteLine("{0} ^ {1} = {2}", a, b, a ^ b);
            Console.WriteLine("~{0} = {1}", a, ~a);

*/


            // De Morgan's laws
            // !(a && b) == (!a || !b)
            // !(a || b) == (!a && !b)

            byte a = 3; // 0000 0011 = 3
            byte b = 5; // 0000 0101 = 5
            Console.WriteLine(a | b); // 0000 0111 = 7
            Console.WriteLine(a & b); // 0000 0001 = 1
            Console.WriteLine(a ^ b); // 0000 0110 = 6
            Console.WriteLine(~a & b); // 0000 0100 = 4
            Console.WriteLine(a << 1); // 0000 0110 = 6
            Console.WriteLine(a << 2); // 0000 1100 = 12
            Console.WriteLine(a >> 1); // 0000 0001 = 1
            // Set the bit in position p to 0
            // n = n & (~(1 << p));
            // set the bit in position p to 1
            // n = n | (1 << p);

            byte result = 23;
            Console.WriteLine(Convert.ToString(result, 2).PadLeft(16, '0'));
            // 0000000000110011

            // Concatenation
            Console.WriteLine(23 + 45 + 45 + "23 this will be concatinated instead of added there is a string operad!"); // 11323 this will be concatinated instead of added there is a string operad!

            bool pr = (1 + 2) * 8 % 4 > (23 + 45) % 34;

            // 3. Console
            Console.WriteLine("Please enetr your age?");
            string input = Console.ReadLine();
            int parsed = int.Parse(input);
            Console.WriteLine("You have entered: {1} {0}", ++parsed, age);

/* Or use try throw catch finally
            try
            {
                age = int.Parse(input);
            }
            catch (System.FormatException e)
            {
                Console.WriteLine("Incorect data!!! {0}", e.Message);
                // throw new System.
            }
            finally
            {
                Console.WriteLine("I am always executed!");
            }
*/

            Console.WriteLine("Hello World! And I am " + age + " years old!");
            Console.WriteLine("I have in my pocket : " + money);
            Console.WriteLine("The first letter of my name is: " + firstLetter);
            Console.WriteLine("Am I a man? : " + isMale);
            Console.WriteLine("My Name is " + name);
            Console.WriteLine("Result: " + pr);

            // 4. Control statements
            if (parsed < 20)
            {
                Console.WriteLine("You are an teenager!");
            }
            else if (parsed >= 20 && parsed <= 30)
            {
                Console.WriteLine("You are in a brilliant stage of your life the! It is time for fun");
            }
            else if (parsed > 30 && parsed <= 40)
            {
                Console.WriteLine("Its time for a family life");
            }
            else {
                Console.WriteLine("You are an old man");
            }

            switch (parsed) { // integar, string enum
                case 21 :
                case 20 :
                    Console.WriteLine("switch You are in perfect age!");
                    break;
                case 50:
                    Console.WriteLine("switch You are in the middle of your life");
                    break;
                default :
                    Console.WriteLine("switch I don't know what to say");
                    break;
            }

            Console.WriteLine(1);
            Console.WriteLine(2);
            Console.WriteLine(3);
            // ...
            Console.WriteLine("1\n2\n3\n");

            int i = 1;
            while (i <= 10) {
                if (i == 5) break;
                Console.WriteLine(i);
                i++;
            }


            Console.WriteLine("Please choose:");
            Console.WriteLine("1. List the partitions");
            Console.WriteLine("2. Create a partition");
            Console.WriteLine("3. Delete partiotion");
            Console.WriteLine("4. Exit");
            string choice = "";
            while (true) {
                //... do something smart
                choice = Console.ReadLine();
                if (choice == "4")
                {
                    break;
                }
            }


            i = 11;
            do
            {
                Console.WriteLine("do-while: - {0}", i);
                i++;
            } while (i <= 10);



            /* Menu
            string choice = "";
            i = 1;
            do
            {
                Console.Clear();
                Console.WriteLine("Моля изберете:");
                Console.WriteLine("1. Пържени яйца");
                Console.WriteLine("2. Фасул");
                Console.WriteLine("3. Пиле с ориз");
                Console.WriteLine("4. Изход");
                // Console.WriteLine("do-while: {0}!", i);
                choice = Console.ReadLine();
                if (choice == "4")
                {
                    break;
                }

                if (choice == "1") {
                    Console.Clear();
                    Console.WriteLine("Натиснете който и да е клавиш, за да се върнете към главното меню!");
                    Console.WriteLine("За да си опържиш яийца ...");
                    choice = Console.ReadLine();
                }

                //if (choice == "1")
                //{
                //    do
                //    {
                //        Console.Clear();
                //        Console.WriteLine("Натиснете 4 за да се върнете към главното меню!");
                //        Console.WriteLine("За да си опържиш яийца ...");
                //        choice = Console.ReadLine();
                //        if (choice == "4") break;
                //    } while (true);

                //}

            }while(true);
            */



            int k;

            for (i = 0; i < 10; i++) {
                if (i % 2 != 1) continue;
                Console.WriteLine("for - {0}", i);
            }

            string[] group2a = { "Milena", "Geri", "Valq", "Maria", "Milena", "Sofia", "Musti", "Virginia", "Slavcho", "Borislav", "Venci", "Rado"};

            Console.WriteLine("The list of group 2a:");
            foreach (string namestr in group2a) {
                Console.WriteLine(namestr);
            }

            // block scoping
            // string namestr; // This is not correct

            // child block scope
            {
                string namestr; // it is OK
            }

            for (i = 0; i < 10; i++) {
                for (int j = 0; j < i; j++) {
                    Console.Write("*");
                }
                Console.WriteLine();
            }

            /* 1.
            int[] myArray;
            myArray = new int[5];
            myArray[4] = 45;
            */

            // 2.
            // int[] myArray = { 23, 45, 67, 89 };

            // 3.
            int[] myArray = new int[5] { 23, 45, 67, 89, 98 };

            for (i = 0; i < myArray.Length; i++) {
                Console.WriteLine("myArray[{0}] = {1}", i, myArray[i]);
            }

            string[,] positionsOfTheStudents = {
                   {"Milena", "Geri","","","","Valq", "","Maria"},
                   {"Milena", "Sofia","","Musti","Virginia","", "","Slavcho"},
                   {"Borislav", "Venci","","Rado","","", "",""}
            };

            for (i = 0; i < positionsOfTheStudents.GetLength(0); i++)
            {
                Console.Write("Red {0}: ", i);
                for (int j = 0; j < positionsOfTheStudents.GetLength(1); j++)
                {
                    Console.Write(" {0}", positionsOfTheStudents[i, j]);
                }
                Console.WriteLine();
            }

            int[][] jaggedArray;
            jaggedArray = new int[2][];
            jaggedArray[0] = new int[8];
            jaggedArray[1] = new int[5];


            byte resultTest = 148;

            // bynary
            Console.WriteLine(Convert.ToString(resultTest, 2).PadLeft(16, '0'));
            Console.WriteLine("{0,10:X}", 148);
            // Console.WriteLine("{0,10:C4}", 148);

            /*
            0000000010010100

            1*2^7 + 1*2^4 + 1* 2^2 = 128 + 16 + 4 = 148

            148 = 1*10^2 + 4*10^1 + 8*10^0 = 100 + 40 +8 = 148

            148 % 2 = 0
            74 % 2 = 0
            37 % 2 = 1
            18 % 2 = 0
            9 % 2 = 1
            4 % 2 = 0
            2 % 2 = 0
                    1

            10010100
            10010100
            */

            /*
            string temp = "";

            for (i = 0; i < 10; i++) {
                temp += "*";
            }

            Console.WriteLine(temp);

            temp = "";
            for (i = 0; i < 5; i++)
            {
                temp += "@";
            }
            Console.WriteLine(temp);

            */

            Console.WriteLine(createString(10));
            Console.WriteLine(createString(5));
            Console.WriteLine(createString(5, "@"));
            Console.WriteLine(createString(12, "^", "Milena", "Geri"));
            Console.WriteLine(createString());

            Console.WriteLine("Factorial from {1} = {0} ", factorial(6), 6);
            Console.WriteLine("Factorial from {1} = {0} ", factorialIteration(6), 6);

            Console.WriteLine("Fibonacci number {1} = {0} ", fibonacci(7), 7);


            Console.WriteLine("Prime numbers:");
            bool isPrime = true;
            for (i = 2; i < 100; i++)
            {
                isPrime = true;
                for (int j = 2; j < i; j++)
                {
                    // if (i % j == 0)
                    if (i % Math.Sqrt(j) == 0) // better
                    {
                        isPrime = false;
                        break;
                    }
                }
                if (isPrime) {
                    Console.WriteLine(i);
                }
            }

            // Pine Tree
            Console.WriteLine("Pine Tree");
            int size = 80;
            for (i = 0; i < size; i++)
            {
                if (i % 2 == 0) continue;
                for (int k = (size - i) / 2; k > 0; k--)
                {
                    Console.Write(" ");
                }
                for (int j = 0; j < i; j++)
                {
                    Console.Write("*");
                }
                Console.WriteLine();
            }

            Console.WriteLine("The number 0xfabc = {0,10:d} ", 0xfabc);
            Console.WriteLine("The number 64188 = {0,10:x}", 64188);

        }

        static string createString(int strLength, string str = "*", params string[] par) {
            string temp = "";
            for (int i = 0; i < strLength; i++)
            {
                temp += str;
            }

            foreach (string item in par)
            {
                Console.WriteLine(item);
            }

            return temp;
        }

        /*
        static string createString(int sadh, string erwrew = "*", params string[] par)
        {
            return "Error!!!";
        }
        */

        static string createString()
        {
            return "Hahahah";
        }

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

        static int factorialIteration(int n)
        {
            var factorial = 1;
            for (int i = 1; i <= n; i++)
            {
                factorial *= i;
            }

            return factorial;
        }

        // Fibonacci Fn = (Fn-2) + (Fn-1)
        // e.g. 1,1,2,3,5,8
        static int fibonacci(int n) {
            if (n <= 2) return 1;
            return  fibonacci(n-2) + fibonacci(n-1);
        }
    }
}