leetcode:66 加一

c++

![class Solution {
public:
    vector plusOne(vector& digits) {
        vector res;
        int digitsLen = digits.size();
        int jingwei = 1;
        for(int i = digitsLen - 1; i >= 0; i--){
            
            if(jingwei == 1){
                digits[i] += 1;
                jingwei = 0;
            } else {
                break;
            }
            
            if(digits[i] == 10){
                digits[i] = 0;
                jingwei = 1;
            }
        }
        if(jingwei == 1){
            res.push_back(1);
            for(int i = 0; i < digitsLen; i++) res.push_back(digits[i]);
            return res;
        } else {
            return digits;
        }
    }
};