LeetCode之“数学”：Plus One

　　题目链接

　　题目要求：

　　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.

　　这道题不难，不过可能会误解是二进制数的相加，切记！程序如下：

class Solution {
public:
    vector<int> plusOne(vector<int>& digits) {
        vector<int> ret;
        int sz = digits.size();
        if(sz == 0)
            return ret;
        
        int carry = 1;
        for(int i = sz - 1; i > -1; i--)
        {
            if(carry + digits[i] == 10)
                ret.insert(ret.begin(), 0);
            else
            {
                ret.insert(ret.begin(), carry + digits[i]);
                carry = 0;
            }
        }
        
        if(carry == 1)
            ret.insert(ret.begin(), 1);
            
        return ret;
    }
};