AdjacencyListGraphApplication.java

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package adjacencylistgraph;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Map;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Locale;
import java.util.Scanner;
import org.omg.PortableInterceptor.SYSTEM_EXCEPTION;

/**
 *
 * @author Yex
 */
public class AdjacencyListGraphApplication {
  
  static class AdjacencyListGraph<Vertex, Edge> {
    
    class EdgePair {
      
      Vertex to;
      Edge weight;
      
      EdgePair(Vertex t, Edge w) {
        to = t;
        weight = w;
      }
      
      @Override
      public int hashCode() {
        return to.hashCode() + weight.hashCode();
      }
      
      @Override
      public boolean equals(Object other) {
        if (other == null) return false;
        if (other == this) return true;
        EdgePair otherEdge = (EdgePair)other;
        return to == otherEdge.to && weight == otherEdge.weight;
      }
      
    }
    
    private HashMap<Vertex, HashSet<EdgePair>> adjacencies = new HashMap<>();
    
    void addVertex(Vertex v) {
      if (adjacencies.get(v) != null)
        throw new IllegalArgumentException("Vertex " + v.toString() + " already exists.");
      else
        adjacencies.put(v, new HashSet<EdgePair>());
    }
    
    void removeVertex(Vertex v) {
      adjacencies.remove(v);
      for (Map.Entry<Vertex, HashSet<EdgePair>> entry : adjacencies.entrySet()) {
        entry.getValue().removeIf(p -> p.to.equals(v));
      }
    }
    
    void addEdge(Vertex from, Vertex to, Edge e) {
//      HashSet<EdgePair> from_adj = adjacencies.get(from);
      HashSet<EdgePair> from_adj = from.equals("Белгород") ? adjacencies.get("Белгород") : adjacencies.get(from);
      if (from_adj == null) {
        throw new IllegalArgumentException("Vertex " + from.toString() + " does not exist.");
//      } if (adjacencies.get(to) == null) {
      } if ((to.equals("Белгород") ? adjacencies.get("Белгород") : adjacencies.get(to)) == null) {
        throw new IllegalArgumentException("Vertex " + to.toString() + " does not exist.");
      } else {
        from_adj.add(new EdgePair(to, e));
      }
    }
    
    void removeEdge(Vertex from, Vertex to, Edge e) {
      HashSet<EdgePair> from_adj = adjacencies.get(from);
      if (from_adj == null) {
        throw new IllegalArgumentException("Vertex " + from.toString() + " does not exist.");
      } if (adjacencies.get(to) == null) {
        throw new IllegalArgumentException("Vertex " + to.toString() + " does not exist.");
      } else {
        from_adj.remove(new EdgePair(to, e));
      }
    }
    
    void getAdjacentVertices(Vertex v) {
      
    }
    
    @Override
    public boolean equals(Object other) {
      if (other == null) return false;
      if (other == this) return true;
      AdjacencyListGraph<Vertex, HashSet<EdgePair>> otherAdjacencyListGraph = 
              (AdjacencyListGraph<Vertex, HashSet<EdgePair>>)other;
      
      return adjacencies.equals(otherAdjacencyListGraph.adjacencies);
    }
    
    public String serialize() {
      StringBuilder res = new StringBuilder();
      for (Map.Entry<Vertex, HashSet<EdgePair>> entry : adjacencies.entrySet())
        res.append(entry.getKey().toString()).append(" ");
      res.append("\n");
      for (Map.Entry<Vertex, HashSet<EdgePair>> entry : adjacencies.entrySet()) {
        Vertex from = entry.getKey();
        for (EdgePair edge : entry.getValue()) {
          res.append(from).append(" ");
          res.append(edge.to.toString()).append(" ");
          res.append(edge.weight.toString()).append(" ");
        }
      }
      
      return res.toString();
    }
    
    void deserialize(String str) {
      String vertexStr = str.split("\n")[0];
      String edgeStr = str.split("\n")[1];
      
      adjacencies.clear();
      for (String from : vertexStr.trim().split(" ")) {
        addVertex((Vertex)from);
      }
      
      String[] edges = edgeStr.trim().split(" ");
      for (int i = 0; i < edges.length; i += 3) {
        addEdge((Vertex)edges[i], (Vertex)edges[i + 1], (Edge)edges[i + 2]);
      }
    }
    
  }
  
  public static String loadFile() {
    Scanner in = null;
    String str = null;
    
    try {
      in = new Scanner(new File("distances.txt"));
      in.useLocale(Locale.US);
      str = in.nextLine().trim();
      str += "\n";
      str += in.nextLine().trim();
    } catch (FileNotFoundException e) {
      System.out.println(e.toString());
    } finally {
      if (in != null) {
        in.close();
      }
    }
    
    return str;
  }

  /**
   * @param args the command line arguments
   */
  public static void main(String[] args) {
    AdjacencyListGraph<String, Integer> graph = new AdjacencyListGraph<>();
    String str = loadFile();
    System.out.println(str);
    graph.deserialize(str);
//    System.out.println(graph.serialize());
    
//    graph.addVertex("A");
//    graph.addVertex("B");
//    graph.addVertex("C");
//    graph.addVertex("D");
//    graph.addVertex("E");
//    graph.addEdge("A", "B", 1);
//    graph.addEdge("A", "C", 2);
//    graph.addEdge("A", "D", 3);
//    
//    AdjacencyListGraph<String, Integer> graph2 = new AdjacencyListGraph<>();
//    graph2.addVertex("A");
//    graph2.addVertex("D");
//    graph2.addVertex("E");
//    graph2.addVertex("B");
//    graph2.addVertex("C");
//    graph2.addEdge("A", "C", 2);
//    graph2.addEdge("A", "B", 1);
//    graph2.addEdge("A", "D", 3);
//    
//    System.out.println(graph.equals(graph2));
//    
//    System.out.println(graph.serialize());
//    graph2.removeVertex("B");
//    System.out.println(graph2.serialize());
//    
//    System.out.println("deserializable:");
//    graph2.deserialize(graph.serialize());
//    System.out.println(graph2.serialize());
  }
  
}