Beispiel #1
0
 private static boolean checkConstraints(int nodes, int n) {
   int neighbours[] = g.getNeighbours(n);
   for (int j = 0; j < neighbours.length; j++) {
     if (neighbours[j] == 1) {
       if (colorOfNode[n] == colorOfNode[j]) return false;
     }
   }
   pruneTheDomain(nodes);
   return true;
 }
Beispiel #2
0
 private static void pruneTheDomain(int nodes) {
   for (int i = 0; i < nodes; i++) {
     if (colorOfNode[i] != 0) {
       int neighbours[] = g.getNeighbours(i);
       for (int j = 0; j < neighbours.length; j++) {
         if (neighbours[j] == 1) {
           for (int k = 0; k < noOfColors; k++) {
             if (domainOfNode[j][k] == colorOfNode[i]) {
               domainOfNode[j][k] = 0;
             }
           }
         }
       }
     }
   }
 }
Beispiel #3
0
 private static boolean checkEverything(int nodes) {
   for (int i = 0; i < nodes; i++) {
     if (colorOfNode[i] != 0) {
       int neighbours[] = g.getNeighbours(i);
       for (int j = 0; j < neighbours.length; j++) {
         if (neighbours[j] == 1) {
           if (colorOfNode[i] == colorOfNode[j]) {
             // System.out.println("color is same " + i + " " + j);
             return false;
           }
         }
       }
     } else {
       // System.out.println("no color");
       return false;
     }
   }
   return true;
 }
Beispiel #4
0
 private static int smallByDomain(int nodes, ArrayList l) {
   int arr[] = g.getSortedDeg();
   int n, nod = 0;
   int m, min = 10000;
   for (int i = 2 * nodes / 3; i >= 0; i--) {
     if (!l.contains(arr[i])) {
       n = arr[i];
       m = 0;
       for (int j = 0; j < noOfColors; j++) {
         if (domainOfNode[i][j] != 0) m++;
       }
       if (m < min) {
         min = m;
         nod = n;
       }
     }
   }
   return nod;
 }
Beispiel #5
0
  private static void colorTheGraph(int nodes) {
    initialiseDomain(nodes);
    int arr[] = g.getSortedDeg();
    ArrayList<Integer> l = new ArrayList<Integer>();
    int n;
    for (int i = nodes - 1; i > 2 * nodes / 3; i--) {
      n = arr[i];
      n = colorNodes(nodes, n);
      boolean check = checkConstraints(nodes, n);
      if (check == false) n = backtrack(nodes, n);
      else l.add(n);
    }

    for (int i = 2 * nodes / 3; i >= 0; i--) {
      n = smallByDomain(nodes, l);
      n = colorNodes(nodes, n);
      boolean check = checkConstraints(nodes, n);
      if (check == false) {
        n = backtrack(nodes, n);
      } else {
        l.add(n);
      }
    }
  }
Beispiel #6
0
  /*
  public static void main(String[] args) {
  	try {
  		// solve(args);
  		solve("-file=gc_70_5");
  	} catch (IOException e) {
  		e.printStackTrace();
  	}
  }
  */
  public static void solve(String args) throws IOException {
    String fileName = null;

    // get the temp file name
    // for (String arg : args) {
    if (args.startsWith("-file=")) {
      fileName = args.substring(6);
    }
    // }
    if (fileName == null) return;

    // read the lines out of the file
    List<String> lines = new ArrayList<String>();

    BufferedReader input = new BufferedReader(new FileReader(fileName));
    try {
      String line = null;
      while ((line = input.readLine()) != null) {
        lines.add(line);
      }
    } finally {
      input.close();
    }

    // parse the data in the file
    String[] firstLine = lines.get(0).split("\\s+");
    int nodes = Integer.parseInt(firstLine[0]);
    int edges = Integer.parseInt(firstLine[1]);

    g = new Graph(nodes, edges);
    g.initialiseGraph();

    for (int i = 1; i < edges + 1; i++) {
      String line = lines.get(i);
      String[] parts = line.split("\\s+");

      g.setEdges(Integer.parseInt(parts[0]), Integer.parseInt(parts[1]));
    }

    noOfColors = g.getMaxDeg();
    // System.out.println(noOfColors);
    colorOfNode = new int[nodes];
    prevColorOfNode = new int[nodes];

    domainOfNode = new int[nodes][noOfColors];
    colorTheGraph(nodes);

    int colorsUsed = 0;
    for (int i = 0; i < nodes; i++) {
      int c = colorOfNode[i];
      if (c > colorsUsed) colorsUsed = c;
    }

    // System.out.println(noOfColors);
    // System.out.println(checkEverything(nodes));
    // prepare the solution in the specified output format

    System.out.println(colorsUsed + " " + 0);
    for (int i = 0; i < nodes; i++) {
      System.out.print(colorOfNode[i] + " ");
    }
    System.out.println("");
  }