[20250723] BOJ / G5 / 노드사이의 거리 / 김수연

Author: suyeun84

suyeun84/202507/23 BOJ G5 노드사이의 거리.md

@@ -0,0 +1,70 @@
+```java
+import java.util.*;
+import java.io.*;
+
+public class boj1240 {
+	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());}
+	static ArrayList<Node>[] map;
+    static boolean[] visit;
+    static int n;
+    static int max;
+
+    public static void main(String[] args) throws Exception {
+    	nextLine();
+        n = nextInt();
+        int m = nextInt();
+        map = new ArrayList[n];
+        visit = new boolean[n];
+
+        for (int i = 0; i < n; i++) {
+            map[i] = new ArrayList<>();
+        }
+
+        for (int i = 0; i < n - 1; i++) {
+        	nextLine();
+            int a = nextInt() - 1;
+            int b = nextInt() - 1;
+            int d = nextInt();
+            map[a].add(new Node(b, d));
+            map[b].add(new Node(a, d));
+        }
+
+        for (int i = 0; i < m; i++) {
+        	nextLine();
+            int a = nextInt() - 1;
+            int b = nextInt() - 1;
+            dfs(a, b, 0);
+            System.out.println(max);
+            max = 0;
+            visit = new boolean[n];
+        }
+    }
+
+    static void dfs(int start, int end, int dist) {
+        if (start == end) {
+            max = dist;
+            return;
+        }
+
+        visit[start] = true;
+        for (int i = 0; i < map[start].size(); i++) {
+            if (!visit[map[start].get(i).next]) {
+                dfs(map[start].get(i).next, end, dist + map[start].get(i).dist);
+            }
+        }
+    }
+}
+
+class Node {
+    int next;
+    int dist;
+
+    public Node(int next, int dist) {
+        this.next = next;
+        this.dist = dist;
+    }
+}
+```