using System;

public class Program

{

        public static void Main()

        {

            Console.WriteLine("Hello World");

            int[] arr = {7,3,2, 1, 5, 4, 8};

            int sum = 10;

            int[] visited = new int[arr.Length];

            bool v1 = calc(sum, visited, arr);

​

            bool v2 = calc(sum, visited, arr);

            bool v3 = calc(sum, visited, arr);

            Console.WriteLine(v1);

            Console.WriteLine(v2);

            Console.WriteLine(v3);

​

        }

​

        public static bool calc(int sum, int[] visited, int[] arr)

        {

​

            if (sum < 0)

                return false;

            if (sum == 0)

            {

                return true;

            }

​

            else

            {

                for (int i = 0; i < visited.Length; i++)

                {

                    if (visited[i] == 0)

                    {

                        visited[i] = 1;

​

                        int[] newV = new int[visited.Length];

                       // Array.Copy(visited, 0, newV, 0, visited.Length);

                        if (calc(sum - arr[i], visited, arr) == true)

                        {

                            return true;

                        }

                        else

                        {

                            visited[i] = 0;

                        }

                    }

                }

​

                return false;

            }

        }

    }