Merge pull request #579 from AlgorithmWithGod/LiiNi-coder

[20250730] BOJ / G4 / 이중 우선순위 큐 / 이인희

Author: ShinHeeEul

LiiNi-coder/202507/30 BOJ 이중 우선순위 큐.md

@@ -0,0 +1,43 @@
+```java
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.util.StringTokenizer;
+import java.util.TreeMap;
+
+public class Main {
+    public static void main(String[] args) throws Exception {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        int T = Integer.parseInt(br.readLine());
+
+        for(int t = 0; t<T; t++){
+            int K = Integer.parseInt(br.readLine());
+            TreeMap<Integer, Integer> map = new TreeMap<>();
+
+            for (int i = 0; i < K; i++) {
+                StringTokenizer st = new StringTokenizer(br.readLine());
+                String command = st.nextToken();
+                int value = Integer.parseInt(st.nextToken());
+
+                if (command.equals("I")) {
+                    map.put(value, map.getOrDefault(value, 0) + 1);
+                } else if (command.equals("D")) {
+                    if (map.isEmpty())
+                        continue;
+                    int key = (value == 1) ? map.lastKey() : map.firstKey();
+                    int count = map.get(key);
+                    if (count == 1) {
+                        map.remove(key);
+                    } else {
+                        map.put(key, count - 1);
+                    }
+                }
+            }
+            if (map.isEmpty()) {
+                System.out.println("EMPTY");
+            } else {
+                System.out.println(map.lastKey() + " " + map.firstKey());
+            }
+        }
+    }
+}
+```