Check valid schedule

is_valid_schedule.cpp

struct Meeting {
	int start, end;
};
struct CompareMeeting {
	bool operator()(const Meeting& a, const Meeting& b) const {
		if (a.start == b.start) return a.end < b.end;
		return a.start < b.start;
	}
};
bool IsValidSchedule(vector<Meeting> meetings) {
	sort(meetings.begin(), meetings.end(), CompareMeeting);
	for (int i = 1; i < meetings.size(); ++i) {
		if (meetings[i - 1].end > meeting[i].start)
			return false;
	}
	return true;
} // O(nlogn) time, O(n) space