Given an integer x, return true if x is palindrome integer.
An integer is a palindrome when it reads the same backward as forward.
For example, 121 is a palindrome while 123 is not.
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.
Constraints:
- -231 <= x <= 231 - 1
Follow up: Could you solve it without converting the integer to a string?
class Solution {
public boolean isPalindrome(int x) {
if(x<0){
return false;
}
int origin = x;
int sum = 0;
while(x!=0){
sum = sum*10 + x%10;
x /= 10;
}
return sum==origin;
}
}