证明一个数学猜想遇到的问题

Question

http://topic.csdn.net/u/20080705/16/a9070b29-c658-47bc-8807-95b1d700a69f.html

Answer 1

static void Main(string[] args)
        {
            
            //for (int z = 1; z <1000; z++)
            //  {
            //      if(z%2==0 && z%3!=0)
            //      {
            //          if (cacut(z) > 9)
            //          {
            //              Console.WriteLine("这个数字就不行：" + z);
            //          }
            //          else 
            //          {
            //              Console.WriteLine("这个虽然成立：" + z+"但不知道一个更大的数行不行？");
            //          }    
            //       }
   
            //    }
            int z=89765556;
            if (cacut(89765556) > 9)
            {
                Console.WriteLine("这个数字就不行：" +z);
            }
            Console.ReadLine();
        }
        
        private static int cacut(int n)
        {
           int step = 0;
           int result=n;
            while (step < 10 && result>1) 
           {
               int newshu = sum(result);
               if (result % 2 == 0)
               {
                   result = newshu * newshu;
               } 
               else 
               {
                   result = newshu * newshu * newshu;
               }
              step++;
        }        return step;
    }        private static int sum(int xy)
        {
            int sum = 0;
            while (xy >= 10)
            {
                sum += xy % 10;
                xy = xy / 10;
            }
            return sum + xy;
        }    }

Answer 2

static void Main(string[] args)
        {
            
            //for (int z = 1; z <1000; z++)
            //  {
            //      if(z%2==0 && z%3!=0)
            //      {
            //          if (cacut(z) > 9)
            //          {
            //              Console.WriteLine("这个数字就不行：" + z);
            //          }
            //          else 
            //          {
            //              Console.WriteLine("这个虽然成立：" + z+"但不知道一个更大的数行不行？");
            //          }    
            //       }
   
            //    }
            int z=89765556;
            if (cacut(89765556) > 9)
            {
                Console.WriteLine("这个数字就不行：" +z);
            }
            Console.ReadLine();
        }
        
        private static int cacut(int n)
        {
           int step = 0;
           int result=n;
            while (step < 10 && result>1) 
           {
               int newshu = sum(result);
               if (result % 2 == 0)
               {
                   result = newshu * newshu;
               } 
               else 
               {
                   result = newshu * newshu * newshu;
               }
              step++;
        }        return step;
    }        private static int sum(int xy)
        {
            int sum = 0;
            while (xy >= 10)
            {
                sum += xy % 10;
                xy = xy / 10;
            }
            return sum + xy;
        }    }