[20250926] BOJ / G4 / 작업 / 이종환

0224LJH/202509/26 BOJ 작업.md

@@ -0,0 +1,86 @@
+```java
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.*;
+
+class Main {
+
+	static int nodeCnt,ans;
+	static Node[] nodes;
+
+	static class Node{
+		int startTime = 0;
+		int cost;
+		int parentLeft;
+
+		HashSet<Node> children = new HashSet<>();
+
+		public Node() {
+
+		}
+
+	}
+
+    public static void main(String[] args) throws NumberFormatException, IOException {
+       init();
+       process();
+       print();
+
+    }
+
+
+    public static void init() throws NumberFormatException, IOException {
+    	BufferedReader br= new BufferedReader(new InputStreamReader(System.in));;
+    	nodeCnt = Integer.parseInt(br.readLine());
+    	nodes = new Node[nodeCnt+1];
+    	ans = 0;
+
+    	for (int i = 1; i <=nodeCnt; i++) {
+    		nodes[i] = new Node();
+    	}
+
+    	for (int i = 1; i <= nodeCnt; i++) {
+    		StringTokenizer st = new StringTokenizer(br.readLine());
+    		int cost = Integer.parseInt(st.nextToken());
+
+    		nodes[i].cost = cost;
+
+    		int parentCnt = Integer.parseInt(st.nextToken());
+    		nodes[i].parentLeft = parentCnt;
+    		for (int j = 0; j < parentCnt; j++) {
+    			int nodeNum = Integer.parseInt(st.nextToken());
+    			nodes[nodeNum].children.add(nodes[i]);
+    		}
+
+    	}
+    }
+
+    public static void process() throws IOException {    
+    	Queue<Node> q = new LinkedList<>();
+
+    	for (int i = 1; i<= nodeCnt; i++) {
+    		if (nodes[i].parentLeft == 0) q.add(nodes[i]);
+    	}
+
+
+    	while(!q.isEmpty()) {
+    		Node node = q.poll();
+
+    		int newNum = node.cost + node.startTime;
+    		ans = Math.max(newNum, ans);
+
+    		for (Node child: node.children) {
+    			child.parentLeft--;
+    			child.startTime = Math.max(child.startTime, newNum);
+    			if (child.parentLeft == 0) q.add(child);
+    		}
+    	}
+    }
+
+
+   public static void print() {
+      System.out.println(ans);
+    }
+}
+```