Reverse an Integer

Given a non-negative integer n, return the integer formed by reversing the order of its decimal digits.

The reversal must be performed numerically. If the original number ends with zeroes, those zeroes become leading zeroes after reversal and must be omitted from the resulting integer.

For example, reversing 4821 produces 1284. Reversing 1200 produces 21, not 0021. Reversing 0 produces 0.

Implement the function reverseInteger(n) that returns the reversed integer.

0 <= n <= 2147483647 The reversed result fits within a signed 64-bit integer.