[20251225] BOJ / G3 / 중량제한 / 김민진

Author: zinnnn37

zinnnn37/202512/25 BOJ G3 중량제한.md

@@ -0,0 +1,98 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class BJ_1939_중량제한 {
+
+    private static final BufferedReader  br = new BufferedReader(new InputStreamReader(System.in));
+    private static final BufferedWriter  bw = new BufferedWriter(new OutputStreamWriter(System.out));
+    private static       StringTokenizer st;
+
+    private static int N, M, start, end;
+    private static int[]        maxWeight;
+    private static List<Node>[] graph;
+    private static Queue<Node>  pq;
+
+    private static class Node implements Comparable<Node> {
+        int to;
+        int weight;
+
+        public Node(int to, int weight) {
+            this.to = to;
+            this.weight = weight;
+        }
+
+        @Override
+        public int compareTo(Node o) {
+            return Integer.compare(o.weight, this.weight);
+        }
+
+    }
+
+    public static void main(String[] args) throws IOException {
+        init();
+        sol();
+    }
+
+    private static void init() throws IOException {
+        st = new StringTokenizer(br.readLine());
+        N = Integer.parseInt(st.nextToken());
+        M = Integer.parseInt(st.nextToken());
+
+        graph = new List[N + 1];
+        for (int i = 1; i <= N; i++) {
+            graph[i] = new ArrayList<>();
+        }
+
+        for (int i = 1; i <= M; i++) {
+            st = new StringTokenizer(br.readLine());
+
+            int a = Integer.parseInt(st.nextToken());
+            int b = Integer.parseInt(st.nextToken());
+            int c = Integer.parseInt(st.nextToken());
+
+            graph[a].add(new Node(b, c));
+            graph[b].add(new Node(a, c));
+        }
+
+        maxWeight = new int[N + 1];
+
+        st = new StringTokenizer(br.readLine());
+        start = Integer.parseInt(st.nextToken());
+        end = Integer.parseInt(st.nextToken());
+        maxWeight[start] = Integer.MAX_VALUE;
+
+        pq = new PriorityQueue<>();
+    }
+
+    private static void sol() throws IOException {
+        pq.offer(new Node(start, Integer.MAX_VALUE));
+
+        while (!pq.isEmpty()) {
+            Node cur = pq.poll();
+
+            if (cur.to == end) {
+                bw.write(String.valueOf(cur.weight));
+                bw.flush();
+                bw.close();
+                br.close();
+                return;
+            }
+
+            if (cur.weight < maxWeight[cur.to]) {
+                continue;
+            }
+
+            for (Node next : graph[cur.to]) {
+                int newWeight = Math.min(cur.weight, next.weight);
+
+                if (newWeight > maxWeight[next.to]) {
+                    maxWeight[next.to] = newWeight;
+                    pq.offer(new Node(next.to, newWeight));
+                }
+            }
+        }
+    }
+
+}
+```