LeetCode / plusOne

gistfile1.cpp

vector<int> plusOne(vector<int>& digits) {
	if (digits.empty()) return digits;
	bool overflow = true;
	for (int i = 0; i < digits.size(); ++i) {
		if (digits[i] != 9) {
			overflow = false;
			break;
		}
	}
	int carry = 1;
	int newSize = digits.size() + (overflow ? 1 : 0);
	vector<int> result(newSize, 0);
	int org = digits.size() - 1;
	int dst = result.size() - 1;
	while (org >= 0 && dst >= 0) {
		if (digits[org] == 9 && carry) {
			result[dst] = 0;
		}
		else {
			result[dst] = digits[org] + carry;
			carry = 0;
		}
		org--;
		dst--;
	}
	if (carry > 0) result[0] = carry;
	return result;
}