[20251029] BOJ/ G4 / 작업 / 김수연

[20251029] BOJ/ G4 / 작업 / 김수연

Author: suyeun84

suyeun84/202510/29 BOJ G4 작업.md

@@ -0,0 +1,50 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class boj2056 {
+    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();
+    	int[] time = new int[N+1];
+    	int[] degree = new int[N + 1];
+    	int answer = 0;
+    	ArrayList<ArrayList<Integer>> work = new ArrayList<>();
+    	for (int i = 0; i < N+1; i++) work.add(new ArrayList<>());
+    	for (int i = 1; i <= N; i++) {
+    		nextLine();
+    		time[i] = nextInt();
+    		int M = nextInt();
+    		for (int j = 0; j < M; j++) {
+    			int num = nextInt();
+    			work.get(num).add(i);
+    			degree[i]++;
+    		}
+    	}
+    	// 위상 정렬
+    	Queue<Integer> q = new LinkedList<>();
+    	int[] result = new int[N + 1];
+    	for (int i = 1; i <= N; i++) {
+    		result[i] = time[i];
+    		if (degree[i] == 0) q.add(i);
+    	}
+    	
+    	while(!q.isEmpty()) {
+    		int cur = q.poll();
+    		for (int next : work.get(cur)) {
+    			degree[next]--;
+    			result[next] = Math.max(result[next], result[cur] + time[next]);
+    			if (degree[next] == 0) q.add(next);
+    		}
+    	}
+    	
+    	for (int i = 0; i <= N; i++) answer = Math.max(answer,  result[i]);
+    	System.out.println(answer);
+    }
+}
+```