static bool compare(Interval const& a, Interval const& b) {

return a.start < b.start;

}

bool canAttendMeetings(vector<Interval>& intervals) {

sort(intervals.begin(), intervals.end(), compare);

for(int i = 0; i < (int) intervals.size() - 1; ++i) {

if(intervals[i].end > intervals[i + 1].start) {

return false;

}

}

return true;

}