Reddit Daily Programmer 320 Easy

Easy.cs

using System;
using System.Linq;

namespace Reddit
{
    internal static class Easy
    {
        internal static void Run(int input)
        {
            Run(input, true);
        }

        internal static void Run(int input, bool clockwise)
        {
            int[][] spiral = Build(input);

            if (!clockwise)
            {
                int[][] opposite = new int[input][];
                for (int i = 0; i < input; i++)
                {
                    opposite[i] = new int[input];
                    for (int j = 0; j < input; j++)
                    {
                        opposite[i][j] = spiral[j][i];
                    }
                }

                spiral = opposite;
            }

            var items = spiral
                .Select(r => r
                    .Select(c => c.ToString())
                    .ToList())
                .ToList();

            int width = items.SelectMany(e => e).Max(e => e.Length);

            foreach (var item in items)
            {
                Console.WriteLine(string.Join(" ", 
                    item.Select(e => e.PadLeft(width))));
            }
        }

        internal static int[][] Build(int input)
        {
            const int east = 0, south = 1, west = 2, north = 3;

            int value = 1;
            int square = input * input;

            int direction = east;

            int row = 0, column = 0;

            int[] count = new int[]
            {
                input - 1,
                input - 1,
                0,
                1
            };

            int[][] spiral = new int[input][];
            for (int i = 0; i < input; i++)
            {
                spiral[i] = new int[input];
            }
            spiral[0][0] = 1;

            while (value < square)
            {
                switch (direction)
                {
                    case east:
                        if ((column + 1) > count[east])
                        {
                            count[east] = count[east] - 1;
                            direction = south;
                        }
                        else
                        {
                            column = column + 1;

                            value = value + 1;
                            spiral[row][column] = value;
                        }
                        break;

                    case south:
                        if ((row + 1) > count[south])
                        {
                            count[south] = count[south] - 1;
                            direction = west;
                        }
                        else
                        {
                            row = row + 1;

                            value = value + 1;
                            spiral[row][column] = value;
                        }
                        break;

                    case west:
                        if ((column - 1) < count[west])
                        {
                            count[west] = count[west] + 1;
                            direction = north;
                        }
                        else
                        {
                            column = column - 1;

                            value = value + 1;
                            spiral[row][column] = value;
                        }
                        break;

                    case north:
                        if ((row - 1) < count[north])
                        {
                            count[north] = count[north] + 1;
                            direction = east;
                        }
                        else
                        {
                            row = row - 1;

                            value = value + 1;
                            spiral[row][column] = value;
                        }
                        break;
                }
            }

            return spiral;
        }
    }
}