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
impl Solution {
pub fn reverse(x: i32) -> i32 {
let mut x = x;
let mut rev: i64 = 0; // Use i64 to handle overflow
while x != 0 {
rev = rev * 10 + (x % 10) as i64;
x /= 10;
}
if rev > i32::MAX as i64 || rev < i32::MIN as i64 {
return 0;
}
rev as i32
}
}