Problem Description
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.
Java:
class Solution {
public int reverse(int x) {
if (x == Integer.MIN_VALUE) return 0;
int flag = x > 0 ? 1 : -1;
x *= flag;
int res = 0;
while (x != 0) {
if ((Integer.MAX_VALUE - x%10)/10 < res) return 0;
res = res*10 + x%10;
x /= 10;
}
return res * flag;
}
}
