[20250803] BOJ / G5 / 강의실 배정 / 이준희

JHLEE325/202508/03 BOJ G5 강의실 배정.md

@@ -0,0 +1,52 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    static class study implements Comparable<study> {
+        int start, end;
+
+        study(int s, int e) {
+            start = s;
+            end = e;
+        }
+
+        @Override
+        public int compareTo(study o) {
+            if (this.start != o.start)
+                return Integer.compare(this.start, o.start);
+            return Integer.compare(this.end, o.end);
+        }
+    }
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st;
+        int N = Integer.parseInt(br.readLine());
+
+        study[] studies = new study[N];
+        for (int i = 0; i < N; i++) {
+            st = new StringTokenizer(br.readLine());
+            int s = Integer.parseInt(st.nextToken());
+            int e = Integer.parseInt(st.nextToken());
+            studies[i] = new study(s, e);
+        }
+
+        Arrays.sort(studies);
+
+        PriorityQueue<Integer> pq = new PriorityQueue<>();
+        pq.add(studies[0].end);
+
+        for (int i = 1; i < N; i++) {
+            int curStart = studies[i].start;
+            int curEnd = studies[i].end;
+            if (!pq.isEmpty() && pq.peek() <= curStart) {
+                pq.poll();
+            }
+            pq.add(curEnd);
+        }
+
+        System.out.println(pq.size());
+    }
+}
+```