LeetCode-Plus One

Given a number represented as an array of digits, plus one to the number.

class Solution {
public:
    vector<int> plusOne(vector<int> &digits) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        bool carry=true;
        vector<int> ret;
        ret.resize(digits.size());
        for(int i=digits.size()-1;i>=0;i--){
            ret[i]=digits[i];
            if(carry){
               ret[i]++; 
            }
            if(ret[i]>9){
                ret[i]=ret[i]-10;
                carry=true;
            }
            else carry=false;
        }
        if(carry){
            //ret.push_back(1);
            ret.insert(ret.begin(),1);
        }
        return ret;
    }
};