[20251205] BOJ / G5 / 백도어 / 이종환

Author: 0224LJH

0224LJH/202512/05 BOJ 백도어.md

@@ -0,0 +1,103 @@
+```java
+
+import java.util.StringTokenizer;
+import java.util.*;
+import java.io.*;
+
+public class Main {
+   
+   static StringBuilder sb = new StringBuilder();
+   static HashSet<Integer> set = new HashSet<>();
+   static int nodeCnt,edgeCnt;
+   static long ans = -1;
+   static long[] dis;
+   static Node[] nodes;
+   static boolean[] canGo,visited;
+   
+   static class Node implements Comparable<Node>{
+	   int num;
+	   Map<Integer, Integer> to;
+	   
+	   public Node (int num) {
+		   this.num = num;
+		   to = new HashMap<>();
+	   }
+	   
+	   public int compareTo(Node n) {
+		   return Long.compare(dis[this.num], dis[n.num]);
+	   }
+   }
+  
+
+    public static void main(String[] args) throws IOException {
+    	init();
+    	process();
+    	print();
+
+    }
+    
+    private static void init() throws IOException{
+    	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    	StringTokenizer st = new StringTokenizer(br.readLine());
+    	nodeCnt = Integer.parseInt(st.nextToken());
+    	edgeCnt = Integer.parseInt(st.nextToken());
+    	
+    	nodes = new Node[nodeCnt];
+    	visited = new boolean[nodeCnt];
+    	canGo = new boolean[nodeCnt];
+    	dis = new long[nodeCnt];
+    	Arrays.fill(dis, Long.MAX_VALUE);
+    	dis[0] = 0;
+    	
+    	for (int i = 0; i < nodeCnt; i++) {
+    		nodes[i] = new Node(i);
+    	}
+    	
+    	st = new StringTokenizer(br.readLine());
+    	for (int i = 0; i < nodeCnt; i++) {
+    		canGo[i] = (Integer.parseInt(st.nextToken()) == 1);
+    	}
+    	
+    	for (int i = 0; i < edgeCnt; i++) {
+    		st = new StringTokenizer(br.readLine());
+    		int from = Integer.parseInt(st.nextToken());
+    		int to = Integer.parseInt(st.nextToken());
+    		int cost = Integer.parseInt(st.nextToken());
+    		
+    		nodes[from].to.put(to,cost);
+    		nodes[to].to.put(from,cost);
+    	}
+    	
+    }
+    
+    private static void process() throws IOException {
+    	PriorityQueue<Node> pq = new PriorityQueue<>();
+    	pq.add(nodes[0]);
+    	
+    	while(!pq.isEmpty()) {
+    		Node n = pq.poll();
+    		if (visited[n.num]) continue;
+    		visited[n.num] = true;
+    		
+    		for (int to: n.to.keySet()) {
+    			if (to != nodeCnt-1 &&  canGo[to]) {
+    				continue;
+    			}
+    			int cost = n.to.get(to);
+    			if (dis[to] > dis[n.num] + cost) {
+    				dis[to] = dis[n.num] + cost;
+    				pq.add(nodes[to]);
+    			}
+    		}
+    	}
+    	
+    	if (dis[nodeCnt-1] != Long.MAX_VALUE) ans = dis[nodeCnt-1];
+    	
+    }
+    
+   private static void print() {
+      System.out.println(ans);
+    }
+
+}
+```