MagicNumbers

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

namespace MagicNumbers
{
    public class Program
    {
        public static void Main()
        {
            // Version 1
            //SolutionStoringResultsInCollection();

            // Version 2
            //SolutionPrintNumberOnConsoleImmediately();

            // Version 3

            //Reading the 'magic number'
            //int magicNumber = int.Parse(Console.ReadLine());
            //int[] number = new int[6];
            //SolutionRecursive(0, magicNumber, number);
        }

        public static void SolutionRecursive(int position, int magicNumber, int[] number)
        {
            if (position >= 6)
            {
                int product = number[0] * number[1] * number[2] * number[3] * number[4] * number[5];
                if (product == magicNumber)
                {
                    string output = string.Join("", number);
                    Console.Write(output);
                    Console.Write(" ");

                }

                return;
            }

            for (int i = 1; i <= 9; i++)
            {
                number[position] = i;

                int nextPosition = position + 1;
                SolutionRecursive(nextPosition, magicNumber, number);
            }
        }

        public static void SolutionStoringResultsInCollection()
        {
            // Reading the 'magic number'
            int magicNumber = int.Parse(Console.ReadLine());

            // Storing all valid outputs
            var result = new List<string>();

            // For each position [1...6], place one digit
            for (int i = 1; i <= 9; i++)
            {
                for (int i1 = 1; i1 <= 9; i1++)
                {
                    for (int i2 = 1; i2 <= 9; i2++)
                    {
                        for (int i3 = 1; i3 <= 9; i3++)
                        {
                            for (int i4 = 1; i4 <= 9; i4++)
                            {
                                for (int i5 = 1; i5 <= 9; i5++)
                                {
                                    var product = i * i1 * i2 * i3 * i4 * i5;

                                    // If the product is equal to the 'magic number', store it
                                    if (product == magicNumber)
                                    {
                                        result.Add($"{i}{i1}{i2}{i3}{i4}{i5}");
                                    }
                                }
                            }
                        }
                    }
                }
            }

            // Joining the result
            var output = string.Join(" ", result.ToArray());

            // Print to 'terminal'
            Console.WriteLine(output);
        }

        public static void SolutionPrintNumberOnConsoleImmediately()
        {
            // Reading the 'magic number'
            int magicNumber = int.Parse(Console.ReadLine());

            // For each position [1...6], place one digit
            for (int i = 1; i <= 9; i++)
            {
                for (int i1 = 1; i1 <= 9; i1++)
                {
                    for (int i2 = 1; i2 <= 9; i2++)
                    {
                        for (int i3 = 1; i3 <= 9; i3++)
                        {
                            for (int i4 = 1; i4 <= 9; i4++)
                            {
                                for (int i5 = 1; i5 <= 9; i5++)
                                {
                                    var product = i * i1 * i2 * i3 * i4 * i5;

                                    // If the product is equal to the 'magic number', print it
                                    if (product == magicNumber)
                                    {
                                        Console.Write($"{i}{i1}{i2}{i3}{i4}{i5}");
                                        Console.Write(" ");
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
    }
}