BOJ #18126: 너구리 구구

Author: ISKU

BOJ/18126/Main.java

@@ -0,0 +1,62 @@
+/*
+ * Author: Minho Kim (ISKU)
+ * Date: November 25, 2019
+ * E-mail: minho.kim093@gmail.com
+ *
+ * https://github.com/ISKU/Algorithm
+ * https://www.acmicpc.net/problem/18126
+ */
+
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+	private static List<Edge>[] graph;
+	private static boolean[] visited;
+	private static int N;
+	private static long answer;
+
+	public static void main(String[] args) throws Exception {
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		N = Integer.parseInt(br.readLine());
+
+		graph = new ArrayList[N + 1];
+		for (int i = 1; i <= N; i++)
+			graph[i] = new ArrayList<Edge>();
+		for (int i = 1; i < N; i++) {
+			StringTokenizer st = new StringTokenizer(br.readLine());
+			int u = Integer.parseInt(st.nextToken());
+			int v = Integer.parseInt(st.nextToken());
+			int w = Integer.parseInt(st.nextToken());
+			graph[u].add(new Edge(v, w));
+			graph[v].add(new Edge(u, w));
+		}
+
+		visited = new boolean[N + 1];
+		answer = 0;
+		dfs(1, 0);
+
+		System.out.println(answer);
+	}
+
+	private static void dfs(int u, long dist) {
+		visited[u] = true;
+		if (u != 1 && graph[u].size() == 1)
+			answer = Math.max(answer, dist);
+
+		for (Edge v : graph[u])
+			if (!visited[v.vertex])
+				dfs(v.vertex, dist + v.weight);
+	}
+
+	private static class Edge {
+		public int vertex;
+		public long weight;
+
+		public Edge(int vertex, long weight) {
+			this.vertex = vertex;
+			this.weight = weight;
+		}
+	}
+}