18

using System;

namespace ConsoleApp3
{
    internal class Program
    {
        static void Main(string[] args)
        {
            int size = 30;
            int[] matrix = new int[size];

            Random random = new Random();
            int randomMaxRange = 10;
            int randomMinRange = 0;

            int step = 1;
            int startPosition = 0;
            int endPosition = matrix.Length - step;

            for (int i = 0; i < size; i++)
            {
                matrix[i] = random.Next(randomMinRange, randomMaxRange);
            }

            if (matrix[startPosition] > matrix[startPosition + step])
            {
                Console.BackgroundColor = ConsoleColor.Green;
                Console.Write(matrix[startPosition]);
                Console.ResetColor();
                Console.Write(" ");
            }
            else
            {
                Console.Write(matrix[startPosition]);
            }

            for (int i = 1; i < size - step; i++)
            {
                if (matrix[i] > matrix[i + step] && matrix[i] > matrix[i - step])
                {
                    Console.BackgroundColor = ConsoleColor.Green;
                    Console.Write(matrix[i]);
                    Console.ResetColor();
                    Console.Write(" ");
                } else
                {
                    Console.Write(matrix[i] + " ");
                }
            }

            if (matrix[endPosition] > matrix[endPosition - step])
            {
                Console.BackgroundColor = ConsoleColor.Green;
                Console.Write(matrix[matrix.Length - step]);
                Console.ResetColor();
                Console.Write(" ");
            }
            else
            {
                Console.Write(matrix[matrix.Length - step]);
            }
        }
    }
}