# 9. Palindrome Number

## Description

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

**Example 1:**

> **Input:** 121&#x20;
>
> **Output:** true

**Example 2:**

> **Input:** -121&#x20;
>
> **Output:** false&#x20;
>
> **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&#x20;
>
> **Output:** false&#x20;
>
> **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?

## code

```java
class Solution {
    public boolean isPalindrome(int x) {
        if (x < 0 || (x != 0 && x % 10 == 0)) return false;
        int rev = 0;
        while(x > rev) {
            rev = rev * 10 + x % 10;
            x /= 10;
        }
        
        return x == rev || x == rev / 10;
        
    }
    
}
```
