MyCalendarI729.java

/**
 * Implement a MyCalendar class to store your events. A new event can be added
 * if adding the event will not cause a double booking.
 * 
 * Your class will have the method, book(int start, int end). Formally, this
 * represents a booking on the half open interval [start, end), the range of
 * real numbers x such that start <= x < end.
 * 
 * A double booking happens when two events have some non-empty intersection
 * (ie., there is some time that is common to both events.)
 * 
 * For each call to the method MyCalendar.book, return true if the event can
 * be added to the calendar successfully without causing a double booking.
 * Otherwise, return false and do not add the event to the calendar.
 * 
 * Your class will be called like this:
 * MyCalendar cal = new MyCalendar(); MyCalendar.book(start, end)
 * 
 * Example 1:
 * MyCalendar();
 * MyCalendar.book(10, 20); // returns true
 * MyCalendar.book(15, 25); // returns false
 * MyCalendar.book(20, 30); // returns true
 * 
 * Explanation: 
 * The first event can be booked.  The second can't because time 15 is already
 * booked by another event.
 * The third event can be booked, as the first event takes every time less
 * than 20, but not including 20.
 * 
 * Note:
 * The number of calls to MyCalendar.book per test case will be at most 1000.
 * In calls to MyCalendar.book(start, end), start and end are integers in the
 * range [0, 10^9].
 */


public class MyCalendarI729 {
    class MyCalendar {
        private TreeSet<Interval> intervals = new TreeSet<>((i1, i2) -> Integer.compare(i1.start, i2.start));
        
        public MyCalendar() {
        }
        
        public boolean book(int start, int end) {
            Interval inv = new Interval(start, end);
            Interval ceiling = intervals.ceiling(inv);
            if (ceiling != null && ceiling.start < end) return false;
            Interval floor = intervals.floor(inv);
            if (floor != null && floor.end > start) return false;
            intervals.add(inv);
            return true;
        }
        
        class Interval {
            int start;
            int end;
            Interval(int s, int e) {
                start = s;
                end = e;
            }
        }
    }
  

    class MyCalendar2 {
        private TreeMap<Integer, Integer> intervals = new TreeMap<>();
        
        public MyCalendar() {
        }
        
        public boolean book(int start, int end) {
            Map.Entry<Integer, Integer> ceiling = intervals.ceilingEntry(start);
            if (ceiling != null && ceiling.getKey() < end) return false;
            Map.Entry<Integer, Integer> floor = intervals.floorEntry(start);
            if (floor != null && floor.getValue() > start) return false;
            intervals.put(start, end);
            return true;
        }
        
    }


/**
 * Your MyCalendar object will be instantiated and called as such:
 * MyCalendar obj = new MyCalendar();
 * boolean param_1 = obj.book(start,end);
 */

}