LeetCode--66. Plus One

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 is at the head of the list.

给出一个数组，这个数组的每一元素代表这个十进制数的位数，如[3,4,5]代表345. 求加1后的结果，结果也以数组这种形式返回

public class Solution {
    public int[] plusOne(int[] digits) {
        int length = digits.length;
        int res = 1;
        for(int i = 0; i < length; i++){
            int sum = digits[length-1-i]+res;
            digits[length-1-i] = sum%10 ;
            res = sum/10;
        }
        if(res!=0){
            int[] result = new int[length+1];
            for(int i =0; i < length; i++){
                result[i] = digits[i];
            }
            result[0] = res;
            return result;
        }
        return digits;
    }
}