乘以字符串烫发

Question

使用以下代码

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

    namespace ConsoleApplication5
    {
        class Program
        {
            public class PermutationFinder<T>
            {
                private T[] items;
                private Predicate<T[]> SuccessFunc;
                private bool success = false;
                private int itemsCount;

                public void Evaluate(T[] items, Predicate<T[]> SuccessFunc)
                {
                    this.items = items;
                    this.SuccessFunc = SuccessFunc;
                    this.itemsCount = items.Count();

                    Recurse(0);
                }

                private void Recurse(int index)
                {
                    T tmp;

                    if (index == itemsCount)
                        success = SuccessFunc(items);
                    else
                    {
                        for (int i = index; i < itemsCount; i++)
                        {
                            tmp = items[index];
                            items[index] = items[i];
                            items[i] = tmp;

                            Recurse(index + 1);

                            if (success)
                                break;

                            tmp = items[index];
                            items[index] = items[i];
                            items[i] = tmp;
                        }
                    }
                }
            }
            static void Main(string[] args)
            {
                new Program().Start();
            }

            void Start()
            {
                string[] items = new string[9];
                items[0] = "1";
                items[1] = "2";
                items[2] = "3";
                items[3] = "5";
                items[4] = "6";
                items[5] = "7";
                items[6] = "8";
                items[7] = "9";
                items[8] = "0";
                new PermutationFinder<string>().Evaluate(items, Evaluate);
                Console.ReadLine();
            }

            public bool Evaluate(string[] items)
            {
                Console.WriteLine(string.Format("{0}{1}{2}{3}{4}{5}{6}{7}{8}", items[0], items[1], items[2], items[3], items[4], items[5], items[6], items[7], items[8]));
                bool someCondition = false;

                if (someCondition)
                    return true;  // Tell the permutation finder to stop.

                return false;
            }

        }
    }

我能够生成序列的排列＆＃34; 1,2,3,5,6,7,8,9,0＆＃34;。 我正在寻找的是一种方法，首先将每个生成的排列转换为整数，将整数乘以2，然后检查它是否是整数的排列＆＃34; 1234567890＆＃34;。如果是，我希望它输出原始整数。有谁知道如何实现这个目标？

谢谢！