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 hold integers within the 32-bit signed integer range. For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.
使用长整型保存结果。依次模 10 得到最右边一位。
class Solution {
public int reverse(int x) {
long result = 0;
for (; x != 0; x /= 10) {
result = result * 10 + x % 10;
}
if (result > Integer.MAX_VALUE || result < Integer.MIN_VALUE) {
return 0;
}
return (int)result;
}
}