Given a 32-bit signed integer, reverse digits of an integer.
Example 1:
Input:
123
Output:
321
Example 2:
Input:
-123
Output:
-321
Example 3:
Input:
120
Output:
21
Note:
Assume we are dealing with an environment which could only store integers within the 32-bit signed integer range: [−231, 231 − 1]. For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.
class Solution {
/**
* @param Integer $x
* @return Integer
*/
function reverse($x) {
$r = (int) (strrev(trim($x,"+-")) * ($x>0?1:-1));
if($r > pow(2,31)-1 || $r < -pow(2,31)){
return 0;
}
return $r;
}
}