C# Loops Ex.14

using System;

class Sphirala
{
    static void Main()
    {
        int colStart, colEnd, oldColEnd;
        int rowStart, rowEnd;
        int rowFix,colFix;
        int col, row;
        int rowIndex, colIndex;
        int num = 1;
        int directionChange = 1;
        int n = int.Parse(Console.ReadLine());

        int[,] matrix = new int[n,n];


        for (int i = 0; i <= n - 1; i++)
        {
            matrix[0, i] = num;
            num++;

        }


        rowStart = rowIndex = 1;
        rowEnd = n - 1;
        colStart = colIndex = n - 2;
        colEnd = 0;
        rowFix = n - 1;
        colFix = n - 1;


        directionChange = 1;

        while (directionChange <= n-1)
        {
            if (directionChange % 2 != 0)                                    // down & left
            {
                for (col = colFix, row = rowStart; row <= rowEnd; row++)
                {

                    matrix[row,col] = num;
                    num++;
                }

                for (row = rowFix, col = colStart; col >= colEnd; col--)
                {

                    matrix[row,col] = num;
                    num++;
                }

                rowEnd = rowStart;
                rowFix = rowStart;
                rowStart = colStart; // new rowStart

                oldColEnd = colEnd;
                colEnd = colStart;
                colFix = oldColEnd; // old colEnd
                colStart = colFix + 1; // new colFix


            }

            else                                                    // up & right
            {
                {
                    for (col = colFix, row = rowStart; row >= rowEnd; row--)
                    {
                        matrix[row, col] = num;
                        num++;
                    }

                    rowFix = rowEnd;



                    for (row = rowFix, col = colStart; col <= colEnd; col++)
                    {
                        matrix[row, col] = num;
                        num++;
                    }


                    colIndex--;
                    rowIndex++;

                    colFix = colEnd; //old colEnd
                    rowFix = rowStart;

                    colEnd = colStart; //old colStar
                    colStart = colIndex;

                    rowEnd = rowStart;
                    rowStart = rowIndex;

                }
            }
            directionChange++;
        }

        for (int rows = 0; rows < matrix.GetLength(0); rows++)
        {
            for (int cols = 0; cols < matrix.GetLength(1); cols++)
            {
                string output = " "+ matrix[rows, cols];
                if (output.Length == 2)
                {
                    output = output + " ";
                }

                Console.Write(output);
            }
            Console.WriteLine();
        }
    }

}