19.1.25 [LeetCode9]Palindrome Number

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?

class Solution {
public:
    bool isPalindrome(int x) {
        if (x < 0)return false;
        int y = 0, _x = x;
        while (_x) {
            y *= 10;
            y += _x % 10;
            _x /= 10;
        }
        return (x == y);
    }
};