Cod sursa(job #2047661)

Utilizator alexnekiNechifor Alexandru alexneki Data 25 octombrie 2017 09:17:53
Problema Algoritmul lui Dijkstra Scor 10
Compilator java Status done
Runda Arhiva educationala Marime 2.2 kb
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.PriorityQueue;
import java.util.Scanner;

public class Main {
  static int n;
  static int m;

  static List<Edge>[] g;
  static int[] dist;
  static boolean[] vis;
  
  static class Edge {
    int to;
    int cost;
    
    Edge(int to, int cost) {
      this.to = to;
      this.cost = cost;
    }
  }
  
  public static void main(String[] args) throws FileNotFoundException, IOException {
    Scanner in =  new Scanner(new BufferedReader(new FileReader("dijkstra.in")));
    PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("dijkstra.out")));

    n = in.nextInt();
    m = in.nextInt();
    
    g = new List[n];
    dist = new int[n];
    vis = new boolean[n];
//    Arrays.fill(g, new ArrayList<>());
    for(int i = 0; i<n; i++)
      g[i] = new ArrayList<>();
    
    Arrays.fill(dist, Integer.MAX_VALUE);
    Arrays.fill(vis, false);
    
    dist[0] = 0;
    for(int i=0; i<m; i++) {
      int from = in.nextInt() - 1;
      int to = in.nextInt() - 1;
      int cost = in.nextInt();
      g[from].add(new Edge(to, cost));
//      out.println(from + ", " + to + ", " + cost);
    }

    PriorityQueue<Long> pq = new PriorityQueue<>();
    pq.add(0L);
    for(int i = 0; i < n; i++) {
      long entry = pq.remove();
      int node = (int) entry;
      for(int j = 0; j < g[node].size(); j++) {
        if(dist[node] + g[node].get(j).cost < dist[g[node].get(j).to]) {
          dist[g[node].get(j).to] = dist[node] + g[node].get(j).cost;
          pq.add(( (1L * dist[g[node].get(j).to]) << 32) + g[node].get(j).to);
        }
      }
    }

    for(int i=1; i<n; i++)
      out.print(dist[i] + " ");
    out.println();
    
//    for(int i=0; i<n; i++) {
//      out.print(i + " -> ");
//      for(int j=0; j<g[i].size(); j++)
//        out.print(g[i].get(j).to + ", ");
//      out.println();
//    }
        
    out.close();
  }
}