732

class MyCalendarThree {
public:
    map<int, int> time;
    MyCalendarThree() {

    }

    int book(int start, int end) {
        time[start]++;
        time[end]--;
        int ans=0, current=0;
        for(auto t: time)
            ans = max(ans, current+=t.second);
        return ans;
    }
};

/**
 * Your MyCalendarThree object will be instantiated and called as such:
 * MyCalendarThree* obj = new MyCalendarThree();
 * int param_1 = obj->book(start,end);
 */