【FB】

小肥的面经，小肥的代码：http://collabedit.com/gmysb

1. 开会的题目，问给一堆会议，每个会议一个开始时间，结束时间，问有没有 overlap

2. 如果这些会议有overlap 求最小需要多少房间

第二个解法简直是精典！

struct Meeting{
    double start;
    double end;
}

struct CompI{
    bool operator()(const Meeting& meet1, const Meeting meet2)
        return meet1.start < meet2.start;
}

bool CheckMeetOverlap(vector<Meeting>& meetings){
    int num = meetings.size();
    if (num<=1)
        return true;
        
    sort(meetings.begin(),meetings.end(),CompI);
    for(int i = 1; i< num; i++){
        if (meetings[i].start < meetings[i-1].end)
            return false;
    }
    return true;
}

//second question
struct MeetingTimePoint{
    double time;
    bool isStart;
    MeetingTimePoint(double time_input, bool isStart_input):time(time_input),isStart(isStart_input){};
}

struct CompII{
    bool operator()(const MeetingTimePoint& meeting1, const MeetingTimePoint& meeting2){
        return meeting1.time<meeting2.time;
    }
}

int minRoom(vector<Meeting>& meetings){
    int num = meetings.size();
    if (num<=1)
        return num;
    
    vector <MeetingTimePoint> meetingInfo; 
    for(int i = 0; i< num; i++){
        MeetingTimePoint current_start = MeetingTimePoint (meetings[i].start, true);
        MeetingTimePoint current_end = MeetingTimePoint (meetings[i].start, false);
        meetingInfo.push_back(current_start);
        meetingInfo.push_back(current_end);        
    }
    sort(meetingInfo.begin(),meetingInfo.end,CompII);
    int currentRoom = 0;
    int minRoom = 0;
    for(int i = 0; i<meetingInfo.size(); i++){
        if (meetingInfo[i].isStart == true)
            currentRoom++;
        else
            currentRoom--;
        minRoom = max(minRoom, currentRoom);
    }
    return minRoom;
}