Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward.

Example 1:

Input: 121
Output: true
Example 2:

Input: -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: 10
Output: false
Explanation: Reads 01 from right to left. Therefore it is not a palindrome.
Follow up:

Coud you solve it without converting the integer to a string?

不转化为String类型，就直接的翻转过来比较两个值是否一样即可。
注意翻转过程中的integer 越界问题，是不需要考虑的。

public boolean isPalindrome(int num) {
		if (num < 0 || (x!=0 && x%10==0)) {
			return false;
		}
		int sum = num;
		int temp = 0;
		while (sum != 0) {
			temp = temp * 10 + sum % 10;
			sum = sum / 10;
		}
		return temp == num;
	}