LeetCode 66. Plus One

原题链接在这里：https://leetcode.com/problems/plus-one/

题目：

Given a non-negative integer represented as a non-empty array of digits, plus one to the integer.

You may assume the integer do not contain any leading zero, except the number 0 itself.

The digits are stored such that the most significant digit is at the head of the list.

题解：

特殊情况是 全是9时需要新建一个数组。

Time Complexity: O(n). Space: O(n).

AC Java:

public class Solution {
    public int[] plusOne(int[] digits) {
        if(digits == null || digits.length == 0){
            return digits;
        }
        int carry = 1;
        for(int i = digits.length-1; i>=0; i--){
            int cur = (digits[i]+carry)%10;
            carry = (digits[i]+carry)/10;
            digits[i] = cur;
            
            if(carry == 0){
                return digits;
            }
        }
        
        int [] res = new int[digits.length+1];
        res[0] = 1;
        return res;
    }
}

跟上Add Binary.