LeetCode202:Happy Number 。C#版，在vs2010中通过，leetcode中Wrong Answer

 static List<int> nums = new List<int>();
        public static bool IsHappy(int n)
        {
            int newint = 0;
            while (n != 0)
            {
                newint += ((n % 10) * (n % 10));
                n = n / 10;
            }
            if (newint == 1)
                return true;
            if (nums.Contains(newint))
            {
                return false;
            }
            else
            {
                nums.Add(newint);
            }

            return IsHappy(newint);
        }