66.Plus One

タイトル:
Given a non-negative number represented as an array of digits、plus one to the number.
The digits are stored such that the most significant digit ist the head of the list.
リンク:  http://leetcode.com/problems/plus-one/
クイズ:
Time Coplexity-O（n），Space Coplexity-O（n）。

public class Solution {

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

        int carry = 1;

        for(int i = digits.length - 1; i >= 0; i --){

            int curValue = digits[i];

            digits[i] = (curValue + carry) % 10;

            carry = (curValue + carry) >= 10 ? 1 : 0;

        }

        

        if(carry == 1){

            int[] result = new int[digits.length + 1];

            result[0] = 1;

            for(int i = 1; i < result.length; i ++){

                result[i] = digits[i - 1];

            }

            return result;

        } else 

            return digits;

    }

}

 
テスト：