Leetcode Plus One

    vector<int> plusOne(vector<int> &digits) {
        int carry = 1;
        for(int i = digits.size() -1 ; i >= 0; -- i){
            
            int value = digits[i] +carry;
            carry = value/10;
            digits[i] = value%10;
        }
        if(carry == 0) return digits;
        else{
            vector<int> res(digits.size()+1);
            res[0] = carry;
            copy(digits.begin(),digits.end(),res.begin()+1);
            return res;
        }
    }