static void TestPermutation(string[] args)
        {
            #region 排列
            // 求排列:5个数取3个的任意排列
            int[]        IntArr          = new int[] { 1, 2, 3, 4, 5 };                                //整型数组
            List <int[]> ListCombination = PermutationAndCombination <int> .GetPermutation(IntArr, 3); //求全部的5取3排列

            foreach (int[] arr in ListCombination)
            {
                foreach (int item in arr)
                {
                    Console.Write(item + " ");
                }
                Console.WriteLine("");
            }
            #endregion
        }
        static void TestCombination(string[] args)
        {
            #region 组合
            // 求组合:求5个数里任意3个数的组合
            int[]        IntArr          = new int[] { 1, 2, 3, 4, 5 };                                //整型数组
            List <int[]> ListCombination = PermutationAndCombination <int> .GetCombination(IntArr, 3); //求全部的3-3组合

            foreach (int[] arr in ListCombination)
            {
                foreach (int item in arr)
                {
                    Console.Write(item + " ");
                }
                Console.WriteLine("");
            }
            Console.ReadKey();
            #endregion
        }