Spiral Matrix

using System;

class SpiralMatrix
{
    private static void ChangeDir(ref string dir) {
        if (dir == "Right"){
            dir = "Down";
        }else if (dir == "Down") {
            dir = "Left";
        }else if(dir == "Left"){
            dir = "Up";
        }else{
            dir = "Right";
        }
    }

    static void Main(string[] args)
    {
        int n = int.Parse(Console.ReadLine());

        int top = 0;
        int left = 0;
        int bottom = n - 1;
        int right = n - 1;
        int counter = 1;
        string dir = "Right";
        int[,] arr = new int[n,n];

        while (top <= bottom && left <= right)
        {
            if (dir == "Right") {
                for (int i = left; i <= right; i++)
                {
                    arr[top, i] = counter++;
                }
                top++;
                ChangeDir(ref dir);
            }
            else if (dir == "Down") {
                for (int i = top; i <= bottom; i++)
                {
                    arr[i, right] = counter++;
                }
                right--;
                ChangeDir(ref dir);
            }
            else if (dir == "Left"){
                for (int i = right; i >= left; i--)
                {
                    arr[bottom, i] = counter++;
                }
                bottom--;
                ChangeDir(ref dir);
            }
            else {
                for (int i = bottom; i >= top; i--)
                {
                    arr[i, left] = counter++;
                }
                left++;
                ChangeDir(ref dir);
            }
        }

        for (int i = 0; i < n; i++){
            for (int j = 0; j < n; j++) {
                Console.Write("{0} ", arr[i,j].ToString().PadRight(3, ' '));
            }
            Console.WriteLine();
        }
    }
}