Set

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

namespace OOOPLab8
{
    public class Set
    {
        public int[] elements;
        private int count;
        public Set()
        {
            Console.Write("Введите кол-во элементов в множестве: ");
            this.count = Int32.Parse(Console.ReadLine());
            Fill();
        }
        public Set(int[] arr)
        {
            this.elements = new int[0];
            int i = 0;
            while (i < arr.Length)
            {
                Add(arr[i]);
                i++;
            }
            //this.count = elements.Length;
        }

        public void Fill()
        {
            this.elements = new int[0];
            int i = 0;
            while(i < this.count)
            {
                Console.Write($"Введите {i + 1} значение элемента множества: ");
                int n = Convert.ToInt32(Console.ReadLine());
                Add(n);
                i++;
            }
            //this.count = elements.Length;
        }
        public int IndexOf(int x)
        {
            int index = -1;
            for(int j = 0; j < elements.Length; j++)
            {
                if (elements[j] == x) { index = j; };
            }
            return index;
        }
        public void Add(int x)
        {
            Array.Resize(ref elements, elements.Length + 1);
            if (IndexOf(x) != -1)
            {
                Array.Resize(ref elements, elements.Length - 1);
            }
            else { elements[elements.Length - 1] = x; }
            this.count = elements.Length;
            //Array.Resize(ref elements, elements.Length - 1);
        }
        public void ShowSet()
        {
            foreach(int x in elements)
            {
                Console.WriteLine(x);
            }
        }
        public static Set operator ++(Set set1)
        {
            for (int i = 0; i < set1.elements.Length; i++)
            {
                set1.elements[i]++;
            }
            return set1;
        }
        public static Set operator +(Set set1, Set set2)
        {
            int[] setarray = { };
            var set3 = new Set(setarray);
            foreach(int i in set1.elements)
            {
                set3.Add(i);
            }
            foreach (int i in set2.elements)
            {
                set3.Add(i);
            }
            set3.elements = set3.elements.Distinct().ToArray();
            return set3;
        }
        public static Set operator *(Set set1, Set set2)
        {
            int[] match = new int[0];
            var set3 = new Set(match);
            foreach(var i in set1.elements)
            {
                foreach (var j in set2.elements)
                {
                    if (i == j)
                    {
                        set3.Add(i);
                    }
                }
            }
            return set3;
        }
        public static Set operator /(Set set1, Set set2)
        {
            int[] match = new int[0];
            var set3 = new Set(match);
            foreach(var i in set1.elements)
            {
                if (!set2.elements.Contains(i))
                {
                    set3.Add(i);
                }
            }
            return set3;
        }
        public static bool operator <(Set set1, Set set2)
        {
            if (set1.elements.Length < set2.elements.Length) return true;
            else return false;
        }
        public static bool operator >(Set set1, Set set2)
        {
            if (set1.elements.Length > set2.elements.Length) return true;
            else return false;
        }
        public int this[int i]
        {
            get
            {
                return elements[i];
            }
            set
            {
                elements[i] = value;
            }
        }
    }
}