using System;

​

public class Program

{

    public static void Main()

    {

        int[, ] arr = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}, {13, 14, 15, 16}};

        //TransposeMatrixNaive(arr);

        PrintSpiralMatrix(arr);

    }

​

    public static void PrintSnakeMatrix(int[, ] arr)

    {

        int rows = arr.GetLength(0);

        int cols = arr.GetLength(1);

        for (int i = 0; i < rows; i++)

        {

            if (i % 2 == 0)

            {

                for (int j = 0; j < cols; j++)

                    Console.Write($"{arr[i, j]} ");

            }

            else

            {

                for (int j = cols - 1; j >= 0; j--)

                {

                    Console.Write($"{arr[i, j]} ");

                }

            }

        }

    }

​

    public static void PrintSpiralMatrix(int[, ] arr)

    {

        int rows = arr.GetLength(0);

        int cols = arr.GetLength(1);

        int top = 0, left = 0, right = cols - 1, bottom = rows - 1;

        Print2DMatrix(arr);

        while (top <= bottom && left <= right)

        {

            for (int i = left; i <= right; i++)

                Console.Write($"{arr[top, i]} ");

            top++;

            for (int i = top; i <= bottom; i++)

                Console.Write($"{arr[i, right]} ");

            right--;

            if (top <= bottom)

            {

                for (int i = right; i >= left; i--)

                    Console.Write($"{arr[bottom, i]} ");

                bottom--;

            }

​

            if (left <= right)

            {

                for (int i = bottom; i >= top; i--)

                    Console.Write($"{arr[i, left]} ");

                left++;

            }

        }

    }

​

    public static void BoundryTraversal(int[, ] arr)

    {

        Print2DMatrix(arr);

        int rows = arr.GetLength(0);

        int cols = arr.GetLength(1);

        //When there is only  one row/

        //Then print all the cols of that row

        if (rows == 1)

        {

            for (int i = 0; i < cols; i++)

            {

                Console.Write($"{arr[0, i]} ");

            }

        }

        else if (cols == 1)

        {

            for (int i = 0; i < rows; i++)

            {

                Console.Write($"{arr[i, 0]} ");

            }

        }

        else

        {

            for (int i = 0; i < cols; i++)

                Console.Write($"{arr[0, i]} ");

            for (int i = 1; i < rows; i++)

                Console.Write($"{arr[i, cols - 1]} ");

            for (int i = cols - 2; i >= 0; i--)

                Console.Write($"{arr[rows - 1, i]} ");

            for (int i = rows - 2; i > 0; i--)

                Console.Write($"{arr[i, 0]} ");

        }

    }

​

    public static void Print2DMatrix(int[, ] arr)

    {

        int rows = arr.GetLength(0);

        int cols = arr.GetLength(1);

        for (int i = 0; i < rows; i++)

        {

            for (int j = 0; j < cols; j++)

                Console.Write($"{arr[i, j]} ");

            Console.WriteLine();

        }

​

        Console.WriteLine();

    }

​

    public static void Swap(int[, ] arr, int i, int j)

    {

        //Console.WriteLine($"i-{i}, j-{j}");

        int temp = arr[i, j];

        arr[i, j] = arr[j, i];

        arr[j, i] = temp;

    }

​

    public static void TransposeMatrixNaive(int[, ] arr)

    {

        Print2DMatrix(arr);

        int rows = arr.GetLength(0);

        int cols = arr.GetLength(1);

        int[, ] temp = new int[rows, cols];

        for (int i = 0; i < rows; i++)

        {

            for (int j = 0; j < cols; j++)

            {

                temp[i, j] = arr[j, i];

            }

        }

​

        Print2DMatrix(temp);

    }

​

    public static void TransposeMatrix(int[, ] arr)

    {

        int rows = arr.GetLength(0);

        int cols = arr.GetLength(1);

        for (int i = 0; i < rows; i++)

        {

            for (int j = i + 1; j < cols; j++)

                Swap(arr, i, j);

        }

​

        Print2DMatrix(arr);

    }

​

    public static void Rotate90Deg(int[, ] arr)

    {

        Print2DMatrix(arr);

        TransposeMatrix(arr);

        ReverseColumns(arr);

    }

​

    public static void ReverseColumns(int[, ] arr)

    {

        int rows = arr.GetLength(0);

        int cols = arr.GetLength(1);

        for (int i = 0; i < rows; i++)

        {

            int low = 0, high = rows - 1;

            while (low < high)

            {

                int temp = arr[low, i];

                arr[low, i] = arr[high, i];

                arr[high, i] = temp;

                low++;

                high--;

            }

        }

​

        Print2DMatrix(arr);

    }

}