[20250918] BOJ / G3 / 최소비용 구하기 2 / 김민진

Author: zinnnn37

zinnnn37/202509/18 BOJ G3 최소비용 구하기 2.md

@@ -0,0 +1,124 @@
+```java
+package etc;
+
+import java.io.*;
+import java.util.*;
+
+public class BJ_1779_최소비용_구하기_2 {
+
+	private static final BufferedReader  br = new BufferedReader(new InputStreamReader(System.in));
+	private static final BufferedWriter  bw = new BufferedWriter(new OutputStreamWriter(System.out));
+	private static final StringBuilder   sb = new StringBuilder();
+	private static       StringTokenizer st;
+
+	private static int N, M;
+	private static int start, end;
+
+	private static Dist[]       dist;
+	private static List<Node>[] graph;
+	private static Queue<Node>  q;
+
+	private static class Node implements Comparable<Node> {
+		int to;
+		int weight;
+
+		Node(int to, int weight) {
+			this.to     = to;
+			this.weight = weight;
+		}
+
+		@Override
+		public int compareTo(Node o) {
+			return Integer.compare(this.weight, o.weight);
+		}
+	}
+
+	private static class Dist {
+		int           dist;
+		List<Integer> cities;
+
+		Dist(int dist, int cur) {
+			this.dist   = dist;
+			this.cities = new ArrayList<>();
+			this.cities.add(cur);
+		}
+
+		Dist(int dist, List<Integer> cities) {
+			this.dist   = dist;
+			this.cities = new ArrayList<>(cities);
+		}
+
+		public void add(int v) {
+			this.cities.add(v);
+		}
+	}
+
+	public static void main(String[] args) throws IOException {
+		init();
+		sol();
+	}
+
+	private static void init() throws IOException {
+		N = Integer.parseInt(br.readLine());
+		M = Integer.parseInt(br.readLine());
+
+		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 u = Integer.parseInt(st.nextToken());
+			int v = Integer.parseInt(st.nextToken());
+			int w = Integer.parseInt(st.nextToken());
+
+			graph[u].add(new Node(v, w));
+		}
+
+		st    = new StringTokenizer(br.readLine());
+		start = Integer.parseInt(st.nextToken());
+		end   = Integer.parseInt(st.nextToken());
+
+		q    = new PriorityQueue<>();
+		dist = new Dist[N + 1];
+
+		for (int i = 1; i <= N; i++) {
+			dist[i] = new Dist(Integer.MAX_VALUE, i);
+			dist[i].cities.clear();
+		}
+	}
+
+	private static void sol() throws IOException {
+		q.offer(new Node(start, 0));
+		dist[start] = new Dist(0, start);
+
+		while (!q.isEmpty()) {
+			Node cur = q.poll();
+
+			if (dist[cur.to].dist < cur.weight) continue;
+
+			for (Node n : graph[cur.to]) {
+				int nDist = dist[cur.to].dist + n.weight;
+
+				if (dist[n.to] == null || nDist < dist[n.to].dist) {
+					dist[n.to] = new Dist(nDist, dist[cur.to].cities);
+					dist[n.to].add(n.to);
+					q.offer(new Node(n.to, nDist));
+				}
+			}
+		}
+
+		sb.append(dist[end].dist).append("\n");
+		sb.append(dist[end].cities.size()).append("\n");
+		for (int city : dist[end].cities) {
+			sb.append(city).append(" ");
+		}
+		bw.write(sb.toString());
+		bw.flush();
+		bw.close();
+		br.close();
+	}
+}
+```