Merge pull request #287 from AlgorithmWithGod/03do-new30

[20250325] BOJ / G4 / 해킹 / 신동윤

Author: ShinHeeEul

03do-new30/202503/25 BOJ G4 해킹.md

@@ -0,0 +1,88 @@
+```java
+import java.util.*;
+import java.io.*;
+
+public class Main {
+	
+	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+	static int n, d, c;
+	static List<Info>[] graph; // 인접 리스트
+	
+	static class Info implements Comparable<Info> {
+		int id;
+		int sec;
+		public Info(int id, int sec) {
+			this.id = id;
+			this.sec = sec;
+		}
+		@Override
+		public int compareTo(Info o) {
+			return Integer.compare(this.sec, o.sec);
+		}
+	}
+	
+	public static void main(String[] args) throws IOException {
+		int T = Integer.parseInt(br.readLine());
+		for (int tc = 1; tc <= T; tc++) {
+			input();
+			// 총 감염되는 컴퓨터 수, 마지막 컴퓨터가 감염되기까지 걸리는 시간
+			dijkstra(c);
+		}
+		br.close();
+	}
+	
+	private static void dijkstra(int start) {
+		PriorityQueue<Info> pq = new PriorityQueue<>();
+		
+		int[] dist = new int[n+1];
+		for (int i = 0; i < n+1; i++) {
+			dist[i] = -1;
+		}
+		dist[start] = 0;
+		pq.add(new Info(start, 0));
+		
+		while (!pq.isEmpty()) {
+			Info info = pq.poll();
+			int current = info.id;
+			if (dist[current] < info.sec) continue; // 이미 더 빠르게 방문한 적이 있으면 skip
+			for (Info next : graph[current]) {
+				if (dist[next.id] == -1 || dist[next.id] > dist[current] + next.sec ) { 
+					dist[next.id] = dist[current] + next.sec; 
+					pq.add(next);
+				}
+			}
+		}
+		
+		int cnt = 0;
+		int time = -1;
+		for (int i = 1; i <= n; i++) {
+			if (dist[i] == -1) { continue; }
+			cnt++;
+			time = Integer.max(time, dist[i]);
+		}
+		// 총 감염되는 컴퓨터 수
+		// 감염되기까지 걸리는 시간
+		System.out.println(cnt + " " + time);
+	}
+	
+	private static void input() throws IOException {
+		StringTokenizer st = new StringTokenizer(br.readLine());
+		n = Integer.parseInt(st.nextToken());
+		d = Integer.parseInt(st.nextToken());
+		c = Integer.parseInt(st.nextToken());
+		graph = new List[n+1];
+		for (int i = 1; i < n+1; i++) {
+			graph[i] = new ArrayList<>();
+		}
+		for (int i = 0; i < d; i++) {
+			st = new StringTokenizer(br.readLine());
+			// 컴퓨터 a가 컴퓨터 b를 의존하며, 컴퓨터 b가 감염되면 s초 후 컴퓨터 a도 감염된다.
+			int a = Integer.parseInt(st.nextToken());
+			int b = Integer.parseInt(st.nextToken());
+			int s = Integer.parseInt(st.nextToken());
+			graph[b].add(new Info(a, s));
+		}
+	}
+}
+
+```