(Demo) C# Advanced Exam (17.02.2019) - 02. Excel Functions

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

namespace Advanced
{
    class Program
    {
        static void Main(string[] args)
        {
            var number = int.Parse(Console.ReadLine());

            var header = Console.ReadLine().Split(", ").ToList();

            var rows = number - 1;

            var matrix = new string[rows][];

            for (int row = 0; row < rows; row++)
            {
                var currentRow = Console.ReadLine()
                .Split(", ")
                .ToArray();

                matrix[row] = currentRow;
            }

            var input = Console.ReadLine().Split().ToArray();

            var command = input[0];
            var headerToModify = input[1];

            var indexTomodify = header.IndexOf(headerToModify);

            switch (command)
            {
                case "hide":
                    header.RemoveAt(indexTomodify);

                    Console.WriteLine(string.Join(" | ", header));

                    var newMatrix = matrix.Select(x => x.Where((rr, c) => c != indexTomodify)).ToArray();

                    foreach (var row in newMatrix)
                    {
                        Console.WriteLine(string.Join(" | ", row));
                    }

                    break;

                case "sort":
                    Console.WriteLine(string.Join(" | ", header));

                    var sortedMatrix = matrix.OrderBy(col => col[indexTomodify]).ToArray();

                    foreach (var row in sortedMatrix)
                    {
                        Console.WriteLine(string.Join(" | ", row));
                    }

                    break;

                case "filter":
                    var itemToFilter = input[2];

                    Console.WriteLine(string.Join(" | ", header));

                    var filteredMatrix = matrix.Where(item => item[indexTomodify] == itemToFilter).ToArray();

                    foreach (var row in filteredMatrix)
                    {
                        Console.WriteLine(string.Join(" | ", row));

                    }

                    break;
            }

        }
    }
}