[LeetCode] Plus One

Thought:
It is an easy array problem.


Code:
public class Solution {
    public int[] plusOne(int[] digits) {
       
        if(digits.length == 0) return digits;

        int n = digits.length, carry = 1;
        for (int i = n - 1; i >= 0; i--) {
            int sum = digits[i] + carry;
            digits[i] = sum % 10;
            carry = sum / 10;
        }

        if (carry == 0) return digits;
        else {
            int[] ret = new int[n + 1];
            ret[0] = 1;
            for (int i = 1; i < n + 1; i++) {
                ret[i] = digits[i - 1];
            }
            return ret;
        }        
    }
}