using System;

namespace DemoApplication

{

    class prime

    {

        private int number; // field

        public int Number   // property

        {

            get { return number; }

            set { number = value; }

        }

        public int getnextprimenumber(int n)

        {

            int nextprime = 0;

            bool primeornot = true;

            int primecount = n + 1;

            int countcheck;

            while (primeornot)

            {

                countcheck = 1;

                int mid = primecount / 2;

                for (int i = 2; i <= mid; i++)

                {

                    if (primecount % i == 0)//not a prime

                    {

                        countcheck = 0;

                        break;

                    }

                    else

                    {

                        countcheck++;

                    }

                }

                if (countcheck == (primecount / 2))// Prime No Found

                {

                    nextprime = primecount;// prime number

                    primeornot = false;// stop the loop                    

                }

                else// Not a Prime number

                {

                    primecount++;// move to next number

                    primeornot = true;

                }

            };

            return nextprime;

        }

​

    }

​

    //Create a function that will remove all duplicate values from this array:

    //int[] arr1 = new int[] { 7, 7, 8, 8, 9, 1, 1, 4, 2, 2 };

    class arrayoperations

    {

        private int[] arr;

        public int[] Arr

        {

            get { return arr; }

            set { arr = value; }

        }

​

        public void duplicatevalueremove(int[] passedarr)

        {

            int lengthofarray = passedarr.Length;

​

            //Ist Loop 

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

            {

                int count = 0;

                //2nd Loop from next position in an array

                for (int j = i + 1; j < lengthofarray; j++)

                {

                    if (passedarr[i] == passedarr[j])

                    {

                        for (int m = j; m < lengthofarray - 1; m++)

                        // third loop for removing the duplicate element in an array

                        {

                            passedarr[m] = passedarr[m + 1];

                        }

                        lengthofarray--;

                        j--;

                        count = 1;

                    }

​

                }

                //removing an 

                if (count == 1)

                {

                    for (int p = i; p < lengthofarray - 1; p++)

                    // to remove the indexed element which was repeated

                    {

                        passedarr[p] = passedarr[p + 1];

                    }

                    lengthofarray -= 1;

                    i--;

                }

            }

​

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

            {

                Console.WriteLine(passedarr[i]);

            }

        }

    }

    //    Usually when you sign up for an account to buy something, your credit card number, phone

    //number or answer to a secret question is partially obscured in some way.Since someone

    //could look over your shoulder, you don't want that shown on your screen. Hence, the website

    //masks these strings.

    //Your task is to create a function that takes a string, transforms all but the last four characters

    //into "#" and returns the new masked string.

    //Examples

    //Maskify("4556364607935616") ➞ "############5616"

    //Maskify("64607935616") ➞ "#######5616"

    //Maskify("1") ➞ "1"

    //Maskify("") ➞ ""

    class MaskingString

    {

        private string string_tobe_masked; // field

        public string String_tobe_masked   // property

        {

            get { return string_tobe_masked; }

            set { string_tobe_masked = value; }

        }

        public string maskingmethod(string smask)

        {

            string maskedstring = "";            

            smask = smask.Replace(" ", "");//removing white spaces

            int strlength = smask.Length;

            if (strlength <= 4)//if length is less than and equal to 4 then no masking reqd

            {

                maskedstring = smask;

            }

            else// Considering all chracters except last 4 characters to be masked

            {

                string last4 = smask.Substring(strlength - 4, 4);

                maskedstring = last4.PadLeft(strlength, '#');

            }

            return maskedstring;

        }

    }

  public class Program

    {

       public static void Main(string[] args)

        {

            // Next Prime Number

            Console.WriteLine("------ Find a Next prime Element ------");

            prime number = new prime();// instantiation of prime class object

            Console.Write("Enter a Integer/Number: ");

            number.Number = Convert.ToInt32(Console.ReadLine());

            int nextprime = number.getnextprimenumber(number.Number);

            Console.Write("Next Prime Number is-->> ");

            Console.WriteLine(nextprime);

           Console.WriteLine("");

            Console.WriteLine("Press Enter for Masking Magic");

            Console.ReadLine();

​

            // Masking String

            Console.WriteLine("------ String Masking ------");

            MaskingString masked_aString = new MaskingString();// instantiation of maskingstring class object

            Console.Write("Enter a String to be masked: ");

            masked_aString.String_tobe_masked = Convert.ToString(Console.ReadLine());

            string maskedstring = masked_aString.maskingmethod(masked_aString.String_tobe_masked);

            Console.Write("Masked String is-->> ");

            Console.WriteLine(maskedstring);

            Console.WriteLine("");

            Console.WriteLine("------ Removal of Duplicate Elements in an Array ------");

            Console.WriteLine("Press Enter removing duplicate elements in an array { 7, 7, 8, 8, 9, 1, 1, 4, 2, 2 }");

            Console.ReadLine();

​

            //arr repeated element deletion

            Console.WriteLine("------ Array Duplicate Value Removal  ------");

            arrayoperations array_c = new arrayoperations();// instantiation of maskingstring class object            

            int[] arr_element = new int[] { 7, 7, 8, 8, 9, 1, 1, 4, 2, 2 };

            array_c.duplicatevalueremove(arr_element);

​

        }

    }

}

​