ControlCSharp/Control/Class5.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Control
{
    internal class Class5
    {
        int[] mass;

        public Class5(int n)
        {
            Random random = new Random();
            mass = new int[n];
            Console.Write("Массив: ");
            for (int i = 0; i < mass.Length; i++)
            {
                mass[i] = random.Next(-50, 51);
                Console.Write($"{mass[i]} ");
            }
            Console.WriteLine();
        }

        public void modifiedArray()
        {
            int[] mass2 = new int[mass.Length];
            int firstOtr = 0;
            int firstPol = 0;

            for (int i = 0; i < mass.Length; i++)
            {
                if (mass[i] < 0)
                {
                    firstOtr = i;
                    break;
                }
            }
            for (int i = 0; i < mass.Length; i++)
            {
                if (mass[i] > 0)
                {
                    firstPol = i;
                    break;
                }
            }
            for (int i = 0; i < mass.Length; i++)
            {
                if (i == firstOtr)
                {
                    mass2[i] = mass[firstPol];
                }
                else if (i == firstPol)
                {
                    mass2[i] = mass[firstOtr];
                }
                else
                {
                    mass2[i] = mass[i];
                }
            }
            Console.Write("Новый массив: ");
            foreach (int el in mass2)
            {
                Console.Write($"{el} ");
            }
            Console.WriteLine();
        }
    }
}