[20250615] BOJ / G3 / 공주님의 정원 / 김수연

suyeun84/202506/15 BOJ G3 공주님의 정원.md

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+```java
+import java.io.*;
+import java.util.*;
+
+public class boj2457 {
+	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+	static StringTokenizer st;
+	static void nextLine() throws Exception {st = new StringTokenizer(br.readLine());}
+	static int nextInt() {return Integer.parseInt(st.nextToken());}
+
+	public static void main(String[] args) throws Exception {
+		nextLine();
+		int N = nextInt();
+		Flower[] flowers = new Flower[N];
+		for (int i = 0; i < N; i++) {
+			nextLine();
+			flowers[i] = new Flower(nextInt()*100 + nextInt(), nextInt()*100 + nextInt());	
+		}
+		Arrays.sort(flowers, (o1, o2)-> {
+			if (o1.start == o2.start) return o2.end - o1.end;
+			return o1.start - o2.start;
+		});
+		int start = 301;
+		int end = 1201;
+		int maxEnd = 0;
+		int answer = 0;
+		int idx = 0;
+		while (start < end) {
+			boolean flag = false;
+			for (int i = idx; i < N; i++) {
+				if (flowers[i].start > start) break;
+				if (flowers[i].end > maxEnd) {
+					maxEnd = flowers[i].end;
+					idx = i+1;
+					flag = true;
+				}
+			}
+			if (flag) {
+				answer++;
+				start = maxEnd;
+			} else break;
+		}
+		System.out.println(maxEnd < end ? "0" : answer);
+	}
+
+	static class Flower {
+		int start, end;
+		public Flower (int start, int end) {
+			this.start = start;
+			this.end = end;
+		}
+	}
+}
+```