using System;

​

class Program

{

    static void Main()

    {

        int[] arr = { 2, 4, 6, 8, 9 };

        PrintArray(arr);

        ReverseInPlace(arr);

        PrintArray(arr);

        int[] arr1 = ReverseToNewArray(arr);

        PrintArray(arr1);

​

        int[][] testArrays = {

            new int[] { 1, 2, 3, 3, 2, 1 },

            new int[] { 1, 2, 3, 2, 1 },

            new int[] { 1, 2, 3, 3, 2 }

        };

​

        foreach (var test in testArrays)

        {

            Console.WriteLine(IsPalindrome1(test));

            Console.WriteLine(IsPalindrome2(test));

        }

    }

​

    static void PrintArray(int[] array)

    {

        Console.WriteLine(string.Join(" ", array));

    }

​

    static void ReverseInPlace(int[] array)

    {

        for (int i = 0, j = array.Length - 1; i < j; i++, j--)

        {

            int temp = array[i];

            array[i] = array[j];

            array[j] = temp;

        }

    }

​

    static int[] ReverseToNewArray(int[] array)

    {

        int[] result = new int[array.Length];

        for (int i = 0; i < array.Length; i++)

            result[i] = array[array.Length - 1 - i];

        return result;

    }

​

    static bool IsPalindrome1(int[] array)

    {

        for (int i = 0, j = array.Length - 1; i < j; i++, j--)

            if (array[i] != array[j])

                return false;

        return true;

    }

​

    static bool IsPalindrome2(int[] array)

    {

        int[] reversed = ReverseToNewArray(array);

        for (int i = 0; i < array.Length; i++)

            if (array[i] != reversed[i])

                return false;

        return true;

    }

}

​