abs for all random negative elements in array that equals to maximum value of array

abs.cs

/*
    Find all absolute values of max value of array.
*/

using System;
using System.Collections.Generic;

namespace lab2
{
    class Program
    {
        public static void array_fill(int n)
        {

        }
        static void Main(string[] args)
        {
            int length;
            int max = 0;

            Console.Write("please input length of array: ");
            length = int.Parse(Console.ReadLine());
            Console.WriteLine();


            // Arrays and lists for storing indexes of max and abs(-max) elements

            int[] rand_array = new int[length];
            List<int> indexes_of_maxes = new List<int>();
            List<int> indexes_of_abs_maxes = new List<int>();

            // Object for creating random values

            Random rand = new Random();

            // Fill array with random values

            for (int i = 0; i < rand_array.Length; i++)
            {
                rand_array[i] = rand.Next(-10, 10);
            }

            // Put to console rand_array elements

            Console.WriteLine("random array contain: ");

            for (int i = 0; i < rand_array.Length; i++)
            {
                Console.WriteLine("rand_array[{0}]={1}", i, rand_array[i]);
            }

            Console.WriteLine();

            // Finding maximum value of array 

            for (int i = 0; i < rand_array.Length; i++)
            {
                if (rand_array[i] > max)
                {
                    max = rand_array[i];
                }
            }

            // Fiding all elemets with max and abs(-max) value and add they indexes to list.

            for (int i = 0; i < rand_array.Length; i++)
            {
                if (rand_array[i] == max)
                {
                    indexes_of_maxes.Add(i);
                }

                if (rand_array[i] < 0 && Math.Abs(rand_array[i]) == max)
                {
                    indexes_of_abs_maxes.Add(i);
                }
            }

            Console.WriteLine("biggest value of rand_array is: {0}", max);
            Console.WriteLine();

            // put to console all elements with max value

            Console.WriteLine("All elements with max value:");

            for (int i = 0; i < indexes_of_maxes.Count; i++)
            {
                Console.WriteLine("rand_array[{0}]", indexes_of_maxes[i]);
            }

            Console.WriteLine();

            // put to console all elements with abs(-max) value

            Console.WriteLine("All elements with abs(-max) value:");

            if (indexes_of_abs_maxes.Count == 0)
            {
                Console.WriteLine("None of the negative elements of rand_array are the abs of max value");
            }
            else
            {
                for (int i = 0; i < indexes_of_abs_maxes.Count; i++)
                {
                    Console.WriteLine("rand_array[{0}]", indexes_of_abs_maxes[i]);
                }
            }

            Console.ReadLine();
        }
    }
}