Maximum Number of Events That Can Be Attended LeetCode solution in Java

1
class Solution {
2
  public int maxEvents(int[][] events) {
3
    Arrays.sort(events, (a, b) -> a[1] == b[1] ? a[0] - b[0] : a[1] - b[1]);
4
    // here sorting the array on ths basis of last day because we want to finish the events which
5
    // happens first,fist.
6

7
    TreeSet<Integer> set = new TreeSet<>();
8
    for (int i = 1; i <= 100000; i++) {
9
      set.add(i);
10
    }
11
    // initliasing a tree set to check available days ;
12
    // a day can go maximum to 100000;
13
    int ans = 0;
14
    for (int i = 0; i < events.length; i++) {
15
      Integer temp = set.ceiling(events[i][0]);
16
      if (temp == null || temp > events[i][1]) continue;
17
      else {
18
        set.remove(temp);
19
        ans += 1;
20
      }
21
    }
22
    return ans;
23
  }
24
}