排列3D的全排列组合

           上午看见有c写的全排列，我也想用C#来实现一下，买过彩票的朋友应该都熟悉3d吧，那么我简单实现一个3d彩票的全排列，3D是从0-9（可能是1-9）这些数字，然后从中选3个数，可以有全排列的买法，也有组合的买法，那么下面贴代码了（vs2008）。

  //-------------------- 全排列和组合排列
class B_Test
    {

        /// <summary>

        /// 对数组进行组合操作，选取selectCount个元素进行组合

        /// </summary>

        /// <param name="lsArray">即将进行组合操作的数组</param>

        /// <param name="selectCount">选取的元素的个数</param>

      public  static void C(List<string> lsArray, int selectCount)

        {

            int totolcount = lsArray.Count;

            int[] currectselect = new int[selectCount];

            int last = selectCount - 1;

 

            for (int i = 0; i < selectCount; i++)

            {

                currectselect[i] = i;

            }

 

            while (true)

            {

                for (int i = 0; i < selectCount; i++)

                {

                    Console.Write(" {0} ", lsArray[currectselect[i]]);

                }

                Console.WriteLine();

 

                if (currectselect[last] < totolcount - 1)

                {

                    currectselect[last]++;

                }

                else

                {

                    int pos = last;

                    while (pos > 0 && currectselect[pos - 1] == currectselect[pos] - 1)

                    {

                        pos--;

                    }

                    if (pos == 0) return;

                    currectselect[pos - 1]++;

                    for (int i = pos; i < selectCount; i++)

                    {

                        currectselect[i] = currectselect[i - 1] + 1;

                    }

                }

            }

        }

      #region

      /// <summary>

      /// 返回组合值（思想是用currectselect记录取的lsArray的每个数对应数组的位置，先把currectselect最后一数加到isarry.cout，接着是倒数第二个加到小于倒数第一个，依次类推知道第0位）

      /// </summary>

      /// <param name="lsArray">即将进行组合操作的数组</param>

      /// <param name="selectCount">选取的元素的个数</param>

      public static List<string> D(List<string> lsArray, int selectCount)
      {

          List<string> list_return=new List<string>();
          int totolcount = lsArray.Count;

          int[] currectselect = new int[selectCount];

          int last = selectCount - 1;



          for (int i = 0; i < selectCount; i++)
          {

              currectselect[i] = i;

          }



          while (true)
          {

              for (int i = 0; i < selectCount; i++)
              {
                  list_return.Add(lsArray[currectselect[i]]);
                  //Console.Write(" {0} ", lsArray[currectselect[i]]);

              }

              //Console.WriteLine();



              if (currectselect[last] < totolcount - 1)
              {

                  currectselect[last]++;

              }

              else
              {

                  int pos = last;

                  while (pos > 0 && currectselect[pos - 1] == currectselect[pos] - 1)
                  {

                      pos--;

                  }

                  if (pos == 0) break;

                  currectselect[pos - 1]++;

                  for (int i = pos; i < selectCount; i++)
                  {

                      currectselect[i] = currectselect[i - 1] + 1;

                  }

              }

          }

          return list_return;

      }

    /// <summary>

    /// list 排列的数组的次序
 
    /// </summary>
    /// <param name="list">排列数组</param>
    /// <param name="selectCount">全排列的个数</param>
      public static void PN(Func<List<string>, int, List<string>> list,List<string> list_input, int selectCount)
      {
          List<string> list_get = new List<string>();
          list_get = list(list_input,selectCount);
          List<string> sub_list = new List<string>();
          foreach (string lis in list_get)
          {
                  sub_list.Add(lis);
              if(sub_list.Count==selectCount)
              {
                A(sub_list,0,selectCount-1);
                sub_list.Clear();
              }
          }
          Console.Write("----------p/n--------");
          Console.WriteLine();
      
      
      }
      #endregion
      /// <summary>

        /// 对数组进行全排列(用全排列的递归思想)

        /// </summary>

        /// <param name="lsArray">要进行全排列的数组</param>

        /// <param name="begin">进行全排列的开始下标</param>

        /// <param name="end">进行全排列的结束下标</param>

      public static void A(List<string> lsArray, int begin, int end)

        {

            if (begin == end)

            {

                for (int i = 0; i <= end; i++)

                Console.Write(" {0} ", lsArray[i]);

                Console.WriteLine();

            }

            for (int i = begin; i <= end; i++)

            {

                Swap(lsArray, begin, i);

                A(lsArray, begin + 1, end);

                Swap(lsArray, begin, i);

            }

        }

 

        /// <summary>

        /// 交换数组中的下标为x,y的值

        /// </summary>

        /// <param name="lsArray">该数组</param>

        /// <param name="x"></param>

        /// <param name="y"></param>

      public static void Swap(List<string> lsArray, int x, int y)

        {

            string t = lsArray[x];

            lsArray[x] = lsArray[y];

            lsArray[y] = t;

        }
    }

对排列3进行操作：

static void Main(string[] args)
        {

            //B_Test b_test = new B_Test();
            List<string> list = new List<string>();
            for (int i = 1; i < 10; i++)
            {

                list.Add(i.ToString());
            }

           // B_Test.PN(B_Test.D(list,3),list,3);
//从数组p中任意选n个数进行全排列p(n)即排列三   
            B_Test.PN((a, b) => B_Test.D(a,b), list, 3);
 //排列3组合
            B_Test.C(list, 3);

            //Console.WriteLine("---------------------");
            
 //数组前n个数的全排列（0，1，2）的全排列  
            B_Test.A(list, 0, 3);
            Console.Read();
}