LeetCode-in-All
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 {
fun reverse(x: Int): Int {
var rev: Long = 0
var localX = x
while (localX != 0) {
rev = (rev * 10) + (localX % 10)
localX /= 10
}
if (rev > Integer.MAX_VALUE || rev < Integer.MIN_VALUE) {
return 0
}
return rev.toInt()
}
}