leetcode inteview code: Plus One

class Solution {
public:
    vector<int> plusOne(vector<int> &digits) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        vector<int> result;
        int carray_bit = 0;
        digits[digits.size()-1] += 1;
        for(int i=digits.size()-1;i>=0;i--) {
            if(carray_bit) {
                result.push_back(1 + digits[i]);
            } else {
                result.push_back(digits[i]);
            }
            if(result[result.size()-1] >= 10) {
                result[result.size()-1] %= 10;
                carray_bit = 1;
            } else {
                carray_bit = 0;
            }
        }
        if(carray_bit) {
            result.push_back(1);
        }
        
        reverse(result.begin(),result.end());
        
        return result;
    }
};