[20251113] PGM / LV3 / 베스트앨범 / 김민진

zinnnn37/202511/13 PGM LV3 베스트엘범.md

@@ -0,0 +1,55 @@
+```java
+import java.util.*;
+
+public class PGM_LV2_베스트엘범 {
+
+    private static int len;
+
+    private static Map<String, Queue<Node>> order;
+    private static Map<String, Integer> cnt;
+
+    private static class Node implements Comparable<Node> {
+        int id;
+        int cnt;
+
+        Node(int id, int cnt) {
+            this.id = id;
+            this.cnt = cnt;
+        }
+
+        @Override
+        public int compareTo(Node o) {
+            return Integer.compare(o.cnt, this.cnt);
+        }
+    }
+
+    public int[] solution(String[] genres, int[] plays) {
+        len = genres.length;
+
+        order = new HashMap<>();
+        cnt = new TreeMap<>(Collections.reverseOrder());
+
+        for (int i = 0; i < genres.length; i++) {
+            cnt.put(genres[i], cnt.getOrDefault(genres[i], 0) + plays[i]);
+
+            order.putIfAbsent(genres[i], new PriorityQueue<>());
+            order.get(genres[i]).offer(new Node(i, plays[i]));
+        }
+
+        List<String> sortedGenres = new ArrayList<>(order.keySet());
+        sortedGenres.sort((a, b) -> Integer.compare(cnt.get(b), cnt.get(a)));
+
+        List<Integer> res = new ArrayList<>();
+
+        for (String genre : sortedGenres) {
+            Queue<Node> pq = order.get(genre);
+
+            for (int i = 0; i < 2 && !pq.isEmpty(); i++) {
+                res.add(pq.poll().id);
+            }
+        }
+
+        return res.stream().mapToInt(i -> i).toArray();
+    }
+}
+```