class Solution { public: vector<int> plusOne(vector<int> &digits) { int len = digits.size(); int carry = 1; int flag; for(int i=len⑴;i>=0;i--){ digits[i]+=carry; flag = digits[i]%10; carry = digits[i]/10; digits[i] = flag; if(!carry) break; } if(carry) digits.insert(digits.begin(),carry); return digits; } };