-
Notifications
You must be signed in to change notification settings - Fork 0
/
ClassRoom.java
57 lines (41 loc) · 1.61 KB
/
ClassRoom.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.PriorityQueue;
import java.util.StringTokenizer;
public class ClassRoom {
private static int[][] resultArr;
public static void main(String[] args) throws Exception {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
StringTokenizer st;
int N = Integer.parseInt(br.readLine());
initResultArr(N);
for(int i = 0; i < N; i++) {
st = new StringTokenizer(br.readLine(), " ");
int startTime = Integer.parseInt(st.nextToken());
int endTime = Integer.parseInt(st.nextToken());
resultArr[i][0] = startTime;
resultArr[i][1] = endTime;
}
Arrays.sort(resultArr, (o1, o2) -> (o1[0] != o2[0])? Integer.compare(o1[0], o2[0]) : Integer.compare(o1[1], o2[1]));
int classRoomCount = getClassRoomCount();
System.out.println(classRoomCount);
}
private static void initResultArr(int length) {
resultArr = new int[length][2];
}
private static int getClassRoomCount() {
PriorityQueue<Integer> resultQueue = new PriorityQueue<>();
resultQueue.offer(resultArr[0][1]);
for(int i = 1; i < resultArr.length; i++) {
int startTime = resultArr[i][0];
int endTime = resultArr[i][1];
int classEndTime = resultQueue.peek();
if(classEndTime <= startTime) {
resultQueue.poll();
}
resultQueue.offer(endTime);
}
return resultQueue.size();
}
}