def reverse(x: Int): Int = {
var _x = x
var result = 0
while (_x != 0) {
result = result * 10 + _x % 10
_x /= 10
}
if (result <= Int.MaxValue && result >= Int.MinValue) result else 0
}
reverse(123)
reverse(-123)
reverse(Int.MinValue)
reverse(Int.MaxValue)