0054-spiral-matrix.cs

public class Solution {
    public IList<int> SpiralOrder(int[][] matrix) {
          List<int> result = new List<int>();
            int top = 0;
            int left = 0;
            int right = matrix[0].Length - 1;
            int bottom = matrix.Length - 1;

            while (true)
            {
                //Left to Right
                for (int i = left; i <= right; i++)
                {
                    result.Add(matrix[top][i]);
                }
                top++;
                if (left > right || top > bottom) break;

                //Top to Bottom
                for (int i = top; i <= bottom; i++)
                {
                    result.Add(matrix[i][right]);
                }
                right--;
                if (left > right || top > bottom) break;

                //Right to Left
                for (int i = right; i >= left; i--)
                {
                    result.Add(matrix[bottom][i]);
                }
                bottom--;
                if (left > right || top > bottom) break;

                //Bottom to Top
                for (int i = bottom; i >= top; i--)
                {
                    result.Add(matrix[i][left]);
                }
                left++;
                if (left > right || top > bottom) break;
            }//Repeat
            return result;
    }
}