BOJ_5972 : 택배 배송

week7/BOJ_5972(택배 배송).java

@@ -0,0 +1,57 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+    public static List<List<int[]>> graph;
+    public static int[] dist;
+    public static int N;
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        N = Integer.parseInt(st.nextToken());
+        int M = Integer.parseInt(st.nextToken());
+        graph = new ArrayList<>();
+        dist = new int[N+1];
+        for(int i=0; i<=N; i++) {
+            graph.add(new ArrayList<>());
+            dist[i] = Integer.MAX_VALUE;
+        }
+        for(int i=0; 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.get(A).add(new int[]{B, C});
+            graph.get(B).add(new int[]{A, C});
+        }
+        dijkstra();
+    }
+
+    public static void dijkstra(){
+        PriorityQueue<int[]> pq = new PriorityQueue<>((o1, o2) -> Integer.compare(o1[1], o2[1]));
+        pq.offer(new int[]{1, 0});
+        while(!pq.isEmpty()) {
+            int v = pq.peek()[0];
+            int cost = pq.peek()[1];
+            pq.poll();
+
+            // 중복 방문 방지
+            if(dist[v] < cost) {
+                continue;
+            }
+
+            List<int[]> list = graph.get(v);
+            for(int i=0; i<list.size(); i++) {
+                int nextV = list.get(i)[0];
+                int nextCost = list.get(i)[1];
+                if(dist[nextV] > cost + nextCost) {
+                    dist[nextV] = cost + nextCost;
+                    pq.offer(new int[]{nextV, dist[nextV]});
+                }
+            }
+        }
+        System.out.println(dist[N]);
+    }
+}