T : o

다익스트라 + 최단 경로

Author: jimi567

Baek Joon백준/다익스트라/11779 - 최소비용 구하기 2.java

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+import java.io.*;
+import java.util.*;
+
+public class Main {
+    static List<Pair>[] adj;
+    static int n;
+    static int m;
+    static int s;
+    static int e;
+
+    static class Pair implements Comparable<Pair>{
+        int cost,v;
+
+        public Pair(int cost,int v){
+            this.cost = cost;
+            this.v = v;
+        }
+
+        @Override
+        public int compareTo(Pair o) {
+            return this.cost - o.cost;
+        }
+    }
+
+    static void solutions(){
+        int[] prev = new int[n+2];
+        int[] d = new int[n+2];
+        Arrays.fill(d,0x3fffffff);
+        PriorityQueue<Pair> pq = new PriorityQueue<>();
+        for(Pair p : adj[s]){
+            if(d[p.v] > p.cost){
+                pq.add(p);
+                d[p.v] = p.cost;
+                prev[p.v] = s;
+            }
+        }
+        d[s] = 0;
+        prev[s] = 0;
+        while(!pq.isEmpty()){
+            var cur = pq.poll();
+            if(d[cur.v] != cur.cost) continue;;
+            for(Pair nxt : adj[cur.v]){
+                if(d[nxt.v] > cur.cost + nxt.cost){
+                    pq.add(new Pair(cur.cost + nxt.cost, nxt.v));
+                    d[nxt.v] = cur.cost + nxt.cost;
+                    prev[nxt.v] = cur.v;
+                }
+            }
+        }
+        System.out.println(d[e]);
+        List<Integer> path = new ArrayList<>();
+        int p = prev[e];
+        path.add(e);
+        while(p != 0){
+            path.add(p);
+            p = prev[p];
+        }
+        System.out.println(path.size());
+        for(int i = path.size()-1 ;i>= 0 ;i--){
+            System.out.printf(path.get(i) + " ");
+        }
+    }
+
+    static void input() throws IOException {
+        try(var br = new BufferedReader(new InputStreamReader(System.in))){
+            var st = new StringTokenizer(br.readLine());
+            n = Integer.parseInt(st.nextToken());
+            st = new StringTokenizer(br.readLine());
+            m = Integer.parseInt(st.nextToken());
+            adj = new ArrayList[n+10];
+            for(int i=1;i<=n;i++) adj[i] = new ArrayList<>();
+            for(int i=0;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());
+                adj[u].add(new Pair(w,v));
+            }
+            st = new StringTokenizer(br.readLine());
+            s = Integer.parseInt(st.nextToken());
+            e = Integer.parseInt(st.nextToken());
+        }
+    }
+
+    public static void main(String[] args) throws IOException {
+        input();
+        solutions();
+    }
+}