leetcode_question_66 Plus One

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

vector<int> plusOne(vector<int> &digits) {        // Start typing your C/C++ solution below        // DO NOT write int main() function        int length = digits.size();        if(length==0)            return digits;        bool carry = true;        int index = length-1;        while(carry && index >= 0)        {            digits[index] += carry;            if(digits[index] > 9)            {digits[index] = 0;carry = true;index--;}            else            {carry = false; break;}        };        if(carry)            digits.insert(digits.begin(), 1);        return digits;    }