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package com.fishercoder.solutions;

/**

* 9. Palindrome Number

*

* Determine whether an integer is a palindrome. Do this without extra space.

*

* Some hints:

*

* Could negative integers be palindromes? (ie, -1)

*

* If you are thinking of converting the integer to string, note the restriction of using extra space.

*

* You could also try reversing an integer. However, if you have solved the problem "Reverse Integer", you know that the reversed integer might overflow. How would you handle such case?

*

* There is a more generic way of solving this problem.

*/

public class _9 {

/**credit: https://discuss.leetcode.com/topic/8090/9-line-accepted-java-code-without-the-need-of-handling-overflow

* reversing only half and then compare if they're equal.*/

public static class Solution1 {

public boolean isPalindrome(int x) {

if (x < 0) {

return false;

} else if (x == 0) {

return true;

} else if (x % 10 == 0) {

return false;

}

int reversed = 0;

while (x > reversed) {

int digit = x % 10;

reversed *= 10;

reversed += digit;

x /= 10;

}

return (x == reversed || x == reversed / 10);

}

}

}