[LeetCode]66 Plus One

public class Solution {
public int[] plusOne(int[] digits) {

if (digits == null || digits.length == 0)
return null;

boolean carry = true;
for (int i = digits.length - 1; i >= 0 ; i --)
{
int v = digits[i];
if (carry)
v++;
carry = v > 9;
v = v % 10;
digits[i] = v;
}

if (!carry)
{
return digits;
}
else
{
int[] r = new int[digits.length + 1];
r[0] = 1;
for (int i = 1 ; i < r.length ; i ++)
{
r[i] = digits[i - 1];
}
return r;
}
}
}