Example 1:

Input: x = 121
Output: true
Explanation: 121 reads as 121 from left to right and from right to left.
Example 2:

Input: x = -121
Output: false
Explanation: From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.
Example 3:

Input: x = 10
Output: false
Explanation: Reads 01 from right to left. Therefore it is not a palindrome.

       static void Main(string[] args)
       {
           IsPalindrome();
       }

       private static void IsPalindrome()
       {
           int x = 121;
            bool isPalindrome = IsPalindrome(x);
            Console.WriteLine($"回文:{isPalindrome}");
            Console.ReadKey();
       }

       private static bool IsPalindrome(int x)
       {
           //負數 或者 個位數是 0 不算 
           if (x < 0 || (x % 10 == 0 && x != 0))
           {
               return false;
           }
           int revertedNumber = 0;
           while (x > revertedNumber)
           {
               revertedNumber = revertedNumber * 10 + x % 10;
               x /= 10;
           }

           return x == revertedNumber || x == revertedNumber / 10;
       }