[20251025] BOJ / G1 / 스카이라인 / 한종욱

Author: Ukj0ng

Ukj0ng/202510/25 BOJ G1 스카이라인.md

@@ -0,0 +1,81 @@
+```
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    private static final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    private static final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+    private static TreeMap<Integer, Integer> buildings;
+    private static List<Event> events;
+    private static int N;
+
+    public static void main(String[] args) throws IOException {
+        init();
+
+        int height = 0;
+        for (Event event : events) {
+            if (event.flag) {
+                buildings.put(event.height, buildings.getOrDefault(event.height, 0)+1);
+                if (height < buildings.lastKey()) {
+                    height = buildings.lastKey();
+                    bw.write(event.x + " " + height + " ");
+                }
+            } else {
+                buildings.put(event.height, buildings.get(event.height)-1);
+                if (buildings.get(event.height) == 0) buildings.remove(event.height);
+                if (height > buildings.lastKey()) {
+                    height = buildings.lastKey();
+                    bw.write(event.x + " " + height + " ");
+                }
+            }
+        }
+
+        bw.flush();
+        bw.close();
+        br.close();
+    }
+
+    private static void init() throws IOException {
+        N = Integer.parseInt(br.readLine());
+
+        events = new ArrayList<>();
+        buildings = new TreeMap<>();
+        buildings.put(0, 1);
+
+        for (int i = 0; i < N; i++) {
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            int l = Integer.parseInt(st.nextToken());
+            int h = Integer.parseInt(st.nextToken());
+            int r = Integer.parseInt(st.nextToken());
+
+            events.add(new Event(l, h, true));
+            events.add(new Event(r, h, false));
+        }
+
+        events.sort((o1, o2) -> {
+            if (o1.x != o2.x) return Integer.compare(o1.x, o2.x);
+            
+            if (o1.flag != o2.flag) {
+                return o1.flag ? -1 : 1;
+            } 
+            
+            if (o1.flag) {
+                return Integer.compare(o2.height, o1.height);
+            }
+            return Integer.compare(o1.height, o2.height);
+        });
+    }
+
+    static class Event {
+        int x;
+        int height;
+        boolean flag;
+
+        public Event(int x, int height, boolean flag) {
+            this.x = x;
+            this.height = height;
+            this.flag = flag;
+        }
+    }
+}
+```