LeetCode-in-Dart
7. Reverse Integer
Medium
Given a signed 32-bit integer x, return x with its digits reversed. If reversing x causes the value to go outside the signed 32-bit integer range [-231, 231 - 1], then return 0.
Assume the environment does not allow you to store 64-bit integers (signed or unsigned).
Example 1:
Input: x = 123
Output: 321
Example 2:
Input: x = -123
Output: -321
Example 3:
Input: x = 120
Output: 21
Example 4:
Input: x = 0
Output: 0
Constraints:
-231 <= x <= 231 - 1
Solution
class Solution {
int reverse(int x) {
int number = x.abs();
int reverseNumber = 0;
final int maxValue = 0x7fffffff;
while (number != 0) {
reverseNumber = reverseNumber * 10 + number % 10;
number = number ~/ 10;
}
if (reverseNumber > maxValue) {
return 0;
}
return x > 0 ? reverseNumber : -reverseNumber;
}
}