using System;

using System.Globalization;

using System.Linq;

using System.Text;

​

namespace TestTask1_KopylenkoYA

{

    class Program

    {

        static void Main(string[] args)

        {

            //Create input array with lines

            string[] inputArray = new string[23] {"INPUT", "Agent ", "Invoice No. 100(2355) ", "2019 - 12 - 31",

                ", open", "Agent ", "Invoice No. 103(1134) ", "2019-11-25", ", credit to ", "2019-12-25", "Agent ",

                "Invoice No. 10(235) ", "2019 - 05 - 25", ", open", "Agent ","Invoice No. 1039(113399) ",

                "2019-05-07", ", credit to ", "2019-06-07", "Agent ", "Invoice No. 100(2352) ", "2019 - 05 - 05", ", closed"};

            StringBuilder inputStringBuilder = new StringBuilder();

​

            //Check if the string contains only digits

            static bool IsDigitsOnly(string str)

            {

                foreach (char c in str)

                {

                    if (!char.IsDigit(c) && c != '-')

                        return false;

                }

                return true;

            }

​

            int numberOfLineINPUT = 0;

            //Formatting and displaying INPUT section

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

            {

                //Check if string element of the array contains "Agent", if yes - Add numberOfLineInput with "Agent" 

                //on new line with format "numberOfLineINPUT: Agent", else add element to StringBuilder

                if (inputArray[i] == "Agent ")

                {

                    numberOfLineINPUT++;

                    string num = String.Concat(numberOfLineINPUT.ToString(), ": ");

                    inputStringBuilder.AppendLine().Append(num);

                    inputStringBuilder.Append(inputArray[i]);

                }

                else

                    inputStringBuilder.Append(inputArray[i]);

            }

​

            Console.WriteLine(inputStringBuilder.ToString());

            StringBuilder outputStringBuilder = new StringBuilder();

            int numberOfLineOUTPUT = 0;

​

            //Formatting and displaying OUTPUT section

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

            {

                if (inputArray[i] == "Agent ")

                {

                    numberOfLineOUTPUT++;

                    string num = String.Concat(numberOfLineOUTPUT.ToString(), ": ");

                    outputStringBuilder.AppendLine().Append(num);

                    outputStringBuilder.Append(inputArray[i]);

                }

                else

                {

                    string resultWithoutWhitespaces = string.Concat(inputArray[i].Where(c => !char.IsWhiteSpace(c)));

​

                    if (IsDigitsOnly(resultWithoutWhitespaces))

                    {

                        DateTime dt = DateTime.ParseExact(resultWithoutWhitespaces, "yyyy-MM-dd", CultureInfo.InvariantCulture);

                        string s = dt.ToString("M'/'d'/'yyyy");

                        outputStringBuilder.Append(s);

                    }

                    else outputStringBuilder.Append(inputArray[i]);

                }

            }

​

            //Replace old string templates with new templates

            outputStringBuilder.Replace("No. ", "#");

            outputStringBuilder.Replace("(", "-");

            outputStringBuilder.Replace(")", "");

            outputStringBuilder.Replace("Invoice", "INVOICE");

            outputStringBuilder.Replace(", open", ", Open");

            outputStringBuilder.Replace(", credit", ", Credit");

            outputStringBuilder.Replace("INPUT", "OUTPUT");

            Console.WriteLine(outputStringBuilder.ToString());

            // commented by Vlad

            //Console.ReadLine();

        }

    }

}

​