Given an array of meeting time intervals consisting of start and end times [[s1,e1],[s2,e2],...] (si < ei), determine if a person could attend all meetings.

For example,
Given [[0, 30],[5, 10],[15, 20]],
return false.

Solution：sort

思路：
Time Complexity: O(nlogn) Space Complexity: O(1)

Solution Code：

class Solution {
    public boolean canAttendMeetings(Interval[] intervals) {
        if (intervals == null) return false;

        // Sort the intervals by start time
        Arrays.sort(intervals, new Comparator<Interval>() {
            public int compare(Interval a, Interval b) { return a.start - b.start; }
        });

        for (int i = 1; i < intervals.length; i++) {
            if (intervals[i].start < intervals[i - 1].end) {
            return false;
            }
        }

      return true;
    }
}