# 9. Palindrome Number (Easy)

https://leetcode.com/problems/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.
```

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

## Solutions

``````class Solution {

public boolean isPalindrome(int x) {
if (x == 0) {
return true;
}

if (x < 0) {
return false;
}

int tmp = x;

int len = 0;
while (tmp != 0) {
tmp = tmp / 10;
len++;
}

int[] stubs = new int[len];

tmp = x;
for (int i = 0; i < len; i++) {
stubs[i] = tmp % 10;
tmp = tmp / 10;
}

int lptr = 0;
int rptr = len - 1;
while (lptr < rptr) {
if (stubs[lptr++] != stubs[rptr--]) {
return false;
}
}

return true;
}
}
``````