// Runtime: 1 ms, faster than 100.00% of Java online submissions for Reverse Integer.
class Solution {
    public int reverse(int x) {
        if (x == 0) return 0;
        if (x == Integer.MIN_VALUE) return 0;

        if (x < 0) return -reverse(-x);

        int r = 0;

        while (x > 0) {
            int d = x % 10;
            r = 10 * r + d;

            if (r % 10 != d) return 0;

            x /= 10;
        }

        return r;
    }
}