[20250204] BOJ / 골드3 / 군사 이동 / 김수연

suyeun84/202502/04 BOJ G3 군사 이동.md

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+```java
+import java.util.*;
+import java.io.*;
+
+class Solution
+{
+    static ArrayList<ArrayList<Point>> graph;
+    static int[] answer;
+
+    public static void main(String[] args) throws Exception{
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        int p = Integer.parseInt(st.nextToken());
+        int w = Integer.parseInt(st.nextToken());
+        st = new StringTokenizer(br.readLine());
+        int c = Integer.parseInt(st.nextToken());
+        int v = Integer.parseInt(st.nextToken());
+        answer = new int[p];
+        graph = new ArrayList<>(p+1);
+
+        for (int i = 0; i < p; i++) {
+            graph.add(new ArrayList<Point>());
+        }
+
+        for (int i = 0; i < w; i++) {
+            st = new StringTokenizer(br.readLine());
+            int start = Integer.parseInt(st.nextToken());
+            int end = Integer.parseInt(st.nextToken());
+            int weight = Integer.parseInt(st.nextToken());
+
+            graph.get(start).add(new Point(end, weight));
+            graph.get(end).add(new Point(start, weight));
+        }
+
+        bfs(c, v);
+        System.out.println(answer[v]);
+    }
+
+    static void bfs(int from, int to) {
+        Queue<Point> q = new LinkedList<>();
+        q.offer(new Point(from, 0));
+        answer[from] = Integer.MAX_VALUE;
+        while (!q.isEmpty()) {
+            Point curr = q.poll();
+            if (curr.e == to) continue;
+            for (Point next : graph.get(curr.e)) {
+            	int nextWieght = Math.min(answer[curr.e], next.w);
+                if (answer[next.e] >= nextWieght) continue;
+                answer[next.e] = nextWieght;
+                q.offer(new Point(next.e, nextWieght));
+            }
+        }
+    }
+
+    static class Point {
+        int e;
+        int w;
+        public Point(int e, int w) {
+            this.e = e;
+            this.w = w;
+        }
+    }
+}
+
+```