66. Plus One

題目地址

注意當輸入爲空時應該輸出1.

class Solution {
public:
    vector<int> plusOne(vector<int> &digits) {
        reverse(digits.begin(), digits.end());
        vector<int> ans;
        int carry = 0;
        for (int i = 0; i < digits.size(); ++i) {
            int plus = i == 0 ? 1 : 0;
            int now = (plus + digits[i] + carry) % 10;
            carry = (plus + digits[i] + carry) / 10;
            ans.push_back(now);
        }
        if (carry) ans.push_back(carry);
        reverse(ans.begin(), ans.end());
        if (ans.size() == 0) ans.push_back(1);
        return ans;
    }
};