30-kokeunho

kokeunho/README.md

@@ -30,4 +30,5 @@
 | 26차시 | 2025.05.19 | 분할 정복 | [별 찍기 - 10](https://www.acmicpc.net/problem/2447) | [#102](https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/102) |
 | 28차시 | 2025.07.01 | 구현 | [스도쿠](https://www.acmicpc.net/problem/2580) |[#116](https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/116) |
 | 29차시 | 2025.07.21 | 그래프 탐색 | [불!](https://www.acmicpc.net/problem/4179) |[#118](https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/118) |
+| 30차시 | 2025.07.26 | 그래프 탐색 | [중량제한](https://www.acmicpc.net/problem/1939) |[#120](https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/120) |
 ---

kokeunho/그래프 탐색/30-kokeunho.java

@@ -0,0 +1,79 @@
+import java.util.*;
+
+public class Main {
+    static int N, M;
+    static List<List<Node>> graph;
+    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 this.weight - o.weight;
+        }
+    }
+
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+
+        N = sc.nextInt();
+        M = sc.nextInt();
+        graph = new ArrayList<>();
+        for (int i = 0; i <= N; i++) {
+            graph.add(new ArrayList<>());
+        }
+
+        int maxWeight = 0;
+        for (int i = 0; i < M; i++) {
+            int from = sc.nextInt();
+            int to = sc.nextInt();
+            int weight = sc.nextInt();
+            graph.get(from).add(new Node(to, weight));
+            graph.get(to).add(new Node(from, weight));
+            maxWeight = Math.max(maxWeight, weight);
+        }
+        int A = sc.nextInt();
+        int B = sc.nextInt();
+
+        int left = 1;
+        int right = maxWeight;
+        int answer = 0;
+
+        while (left <= right) {
+            int mid = (left + right) / 2;
+
+            if (bfs(A, B, mid)) {
+                answer = mid;
+                left = mid + 1;
+            } else {
+                right = mid - 1;
+            }
+        }
+
+        System.out.print(answer);
+    }
+    static boolean bfs(int start, int end, int weightLimit) {
+        Queue<Integer> queue = new LinkedList<>();
+        boolean[] visited = new boolean[N + 1];
+        queue.add(start);
+        visited[start] = true;
+
+        while (!queue.isEmpty()) {
+            int now = queue.poll();
+            if (now == end) return true;
+
+            for (Node next : graph.get(now)) {
+                if (!visited[next.to] && next.weight >= weightLimit) {
+                    queue.add(next.to);
+                    visited[next.to] = true;
+                }
+            }
+        }
+        return false;
+    }
+}