[20250925] BOJ / G2 / 뉴스 전하기 / 이종환

Author: 0224LJH

0224LJH/202509/25 BOJ 뉴스 전하기

@@ -0,0 +1,89 @@
+```java
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.*;
+
+public class Main {
+	
+	static int nodeCnt,ans;
+	static int[] parents;
+	static Node[] nodes;
+	
+	static class Node{
+		int num;
+		int minute = 0;
+		HashSet<Node> children = new HashSet<>();
+		
+		public Node (int num) {
+			this.num = num;
+		}
+		
+		public int calculate() {
+			
+			if (children.size() == 0) {
+				return 0;
+			}
+			PriorityQueue<Integer> pq = new PriorityQueue<>();
+			for (Node c: children) {
+				pq.add(c.calculate());
+			}
+			
+			int min = 0;
+			while (!pq.isEmpty()) {
+				int num = pq.poll();
+				min = Math.max(min, num+pq.size()+1);
+			}
+			
+			
+			
+			
+			return min;
+		}
+		
+	}
+
+
+
+    
+    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());
+		parents = new int[nodeCnt];
+		nodes = new Node[nodeCnt];
+		ans = 0;
+		
+		StringTokenizer st = new StringTokenizer(br.readLine());
+		for (int i = 0; i < nodeCnt; i++) {
+			nodes[i] = new Node(i);
+			parents[i] = Integer.parseInt(st.nextToken());
+			
+		}
+    }
+
+    
+    public static void process() throws IOException { 	
+    	for (int i = 1; i< nodeCnt; i++) {
+    		int parent = parents[i];
+    		nodes[parent].children.add(nodes[i]);
+    	}
+    	ans = nodes[0].calculate();
+
+    }
+
+
+
+
+	public static void print() {
+		System.out.println(ans);
+    }
+}
+```