[20251004] BOJ / G5 / 강의실 / 김수연

[20251004] BOJ / G5 / 강의실 / 김수연

Author: suyeun84

suyeun84/202510/04 BOJ G5 강의실.md

@@ -0,0 +1,52 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class boj1374 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        int n = Integer.parseInt(br.readLine());
+        Lecture[] arr = new Lecture[n];
+        for (int i = 0; i < n; i++) {
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            st.nextToken();
+            int start = Integer.parseInt(st.nextToken());
+            int end = Integer.parseInt(st.nextToken());
+            arr[i] = new Lecture(start, end);
+        }
+        Arrays.sort(arr, (o1, o2) -> o1.start - o2.start);
+        PriorityQueue<Lecture> pq = new PriorityQueue<>();
+        pq.add(arr[0]);
+        for (int i = 1; i < n; i++) {
+            Lecture current = pq.peek();
+            if (current.end <= arr[i].start) {
+                pq.poll();
+                current.end = arr[i].end;
+                pq.add(current);
+            } else {
+                pq.add(arr[i]);
+            }
+
+        }
+        System.out.println(pq.size());
+
+    }
+
+
+    public static class Lecture implements Comparable<Lecture> {
+        int start;
+        int end;
+
+        public Lecture(int start, int end) {
+            this.start = start;
+            this.end = end;
+        }
+
+        @Override
+        public int compareTo(Lecture o) {
+            if (this.end == o.end) return this.start - o.start;
+            return this.end - o.end;
+        }
+    }
+}
+```