14. Array Manipulator

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

namespace _14._Array_Manipulator
{
    class Program
    {
        static void Main(string[] args)
        {

            int[] nums = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
            List<int> list = new List<int>();
            foreach (var num in nums)
            {
                list.Add(num);
            }

            string[] command = Console.ReadLine().Split(' ');


            while (command[0] != "print")
            {
                switch (command[0])
                {
                    case "add":
                        Add(list, command);
                        break;
                    case "addMany":
                        addMany(list, command);
                        break;
                    case "contains":
                        contains(list, command);
                        break;
                    case "remove":
                        Remove(list, command);
                        break;
                    case "shift":
                        Shifting(list, command);
                        break;
                    case "sumPairs":
                        list = SumPairs(list);
                        break;
                }

                command = Console.ReadLine().Split();
            }
            Console.WriteLine("[" + string.Join(", ", list) + "]");
        }

        private static List<int> SumPairs(List<int> list)
        {
            List<int> distinct = new List<int>();
            foreach (var item in list)
            {
                distinct.Add(item);
            }
            for (int i = 0; i < list.Count() / 2; i++)
            {
                distinct[i] = distinct[i] + distinct[i + 1];
                distinct.RemoveAt(i + 1);
            }

            list = distinct;
            return list;
        }

        private static void Remove(List<int> list, string[] command)
        {
            int removed = int.Parse(command[1]);
            list.RemoveAt(removed);
        }

        private static void Add(List<int> list, string[] command)
        {
            int index = int.Parse(command[1]);
            int inserted = int.Parse(command[2]);
            list.Insert(index, inserted);
        }

        private static void addMany(List<int> nums, string[] command)
        {
            int index = int.Parse(command[1]);
            for (int i = command.Length - 1; i >= 2; i--)
            {
                int element = int.Parse(command[i]);
                nums.Insert(index, element);
            }
        }

        private static void contains(List<int> list, string[] command)
        {


            if (list.Contains(int.Parse(command[1])))
            {
                Console.WriteLine(0);
            }
            else
            {
                Console.WriteLine(-1);
            }
        }

        private static void Shifting(List<int> nums, string[] commands)
        {
            int numberOfPositions = int.Parse(commands[1]);
            while (numberOfPositions > 0)
            {
                int first = nums[0];
                nums.RemoveAt(0);
                nums.Add(first);
                numberOfPositions--;
            }
        }
    }
}