66.cpp

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