[LeetCode] Plus One

public class Solution {
    public int[] plusOne(int[] digits) {
        for (int i=digits.length-1; i>=0; i--) {
            if (digits[i] != 9) {
                digits[i] = digits[i] + 1;
                return digits;
            } else {
                digits[i] = 0;
            }
        }
        
        // 说明overflow了，此时原数组全是9
        int [] result = new int[digits.length+1];
        result[0] = 1;
        for (int i=1; i<result.length; i++)
            result[i] = 0;
        return result;
    }
}