Пример #1
0
  // length of shortest ancestral path between any vertex in v and any vertex in w; -1 if no such
  // path
  public int length(Iterable<Integer> v, Iterable<Integer> w) {
    if (!isValid(v)) {
      throw new java.lang.NullPointerException("Invalid v parameter");
    }

    if (!isValid(w)) {
      throw new java.lang.NullPointerException("Ivalid w parameter");
    }

    int shortestLen = G.V() + 1;
    int len = -1;

    for (int iv : v) {
      for (int iw : w) {
        len = length(iv, iw);
        if ((len > 0) && (len < shortestLen)) {
          shortestLen = len;
        }
      }
    }

    if (shortestLen < G.V() + 1) {
      return shortestLen;
    }

    return -1;
  }
Пример #2
0
 // constructor takes a digraph (not necessarily a DAG)
 public SAP(Digraph G) {
   digraph = new Digraph(G.V());
   for (int v = 0; v < G.V(); v++) {
     for (int w : G.adj(v)) {
       digraph.addEdge(v, w);
     }
   }
 }
Пример #3
0
  private boolean isOnlyOneRoot(Digraph g) {
    int total = 0;
    for (int i = 0; i < g.V(); i++) {
      if (g.outdegree(i) == 0) total++;
    }

    return total == 1;
  }
Пример #4
0
 /* do unit testing of this class */
 public static void main(String[] args) {
   System.out.println("Test started file name " + args[0]);
   In in = new In(args[0]);
   Digraph G = new Digraph(in);
   System.out.println("Graph vertices " + G.V() + " graph edges " + G.E());
   System.out.println(G.toString());
   SAP sap = new SAP(G);
   while (!StdIn.isEmpty()) {
     int v = StdIn.readInt();
     int w = StdIn.readInt();
     int length = sap.length(v, w);
     int ancestor = sap.ancestor(v, w);
     StdOut.printf("length = %d, ancestor = %d\n", length, ancestor);
   }
 }
Пример #5
0
  // do unit testing of this class
  public static void main(String[] args) {
    In in = new In(args[0]);
    Digraph G = new Digraph(in);

    StdOut.println(G.toString());

    SAP sap = new SAP(G);
    while (!StdIn.isEmpty()) {
      int v = StdIn.readInt();
      int w = StdIn.readInt();
      int length = sap.length(v, w);
      int ancestor = sap.ancestor(v, w);
      StdOut.printf("length = %d, ancestor = %d\n", length, ancestor);
    }
  }
Пример #6
0
  public WordNet(String synsetFileName, String hyponymFileName) {
    In synsetFile = new In(synsetFileName);
    In hyponymFile = new In(hyponymFileName);
    String[] currentLine;
    String[] splitNouns;

    while (!synsetFile.isEmpty()) {
      currentLine = synsetFile.readLine().split(",");
      map.put(Integer.parseInt(currentLine[0]), currentLine[1]);
      splitNouns = currentLine[1].split(" ");
      for (int i = 0; i < splitNouns.length; i += 1) {
        if (!nouns.contains(splitNouns[i])) {
          nouns.add(splitNouns[i]);
        }
      }
    }
    synsets = new Digraph(map.size());
    while (!hyponymFile.isEmpty()) {
      currentLine = hyponymFile.readLine().split(",");

      for (int i = 1; i < currentLine.length; i++) {
        synsets.addEdge(Integer.parseInt(currentLine[0]), Integer.parseInt(currentLine[i]));
      }
    }
  }
Пример #7
0
  /*
   * length of shortest ancestral path between any vertex in v and any vertex
   * in w; -1 if no such path
   */
  public int length(Iterable<Integer> v, Iterable<Integer> w) {
    for (int vrtx : v) {
      if (!checkVertexInBound(vrtx)) throw new java.lang.IndexOutOfBoundsException();
    }

    for (int vrtx : w) {
      if (!checkVertexInBound(vrtx)) throw new java.lang.IndexOutOfBoundsException();
    }

    BreadthFirstDirectedPaths bfdDirPaths1 = new BreadthFirstDirectedPaths(copyG, v);
    BreadthFirstDirectedPaths bfdDirPaths2 = new BreadthFirstDirectedPaths(copyG, w);

    int minPath = Integer.MAX_VALUE;

    for (int vrtx = 0; vrtx < copyG.V(); vrtx++) {
      int dist1 = bfdDirPaths1.distTo(vrtx);
      int dist2 = bfdDirPaths2.distTo(vrtx);
      int dist = dist1 + dist2;
      if (Integer.MAX_VALUE != dist1 && Integer.MAX_VALUE != dist2 && dist < minPath) {
        minPath = dist;
      }
    }

    if (Integer.MAX_VALUE == minPath) {
      minPath = -1;
    }

    return minPath;
  }
Пример #8
0
  /*
   * a common ancestor of v and w that participates in a shortest ancestral
   * path; -1 if no such path
   */
  public int ancestor(int v, int w) {
    if ((!checkVertexInBound(v)) || (!checkVertexInBound(w)))
      throw new java.lang.IndexOutOfBoundsException();

    BreadthFirstDirectedPaths bfdDirPaths1 = new BreadthFirstDirectedPaths(copyG, v);
    BreadthFirstDirectedPaths bfdDirPaths2 = new BreadthFirstDirectedPaths(copyG, w);

    int minLength = Integer.MAX_VALUE;
    int commAncestor = Integer.MAX_VALUE;

    for (int vrtx = 0; vrtx < copyG.V(); vrtx++) {
      int dist1 = bfdDirPaths1.distTo(vrtx);
      int dist2 = bfdDirPaths2.distTo(vrtx);
      int dist = dist1 + dist2;
      if (Integer.MAX_VALUE != dist1 && Integer.MAX_VALUE != dist2 && dist < minLength) {
        minLength = dist;
        commAncestor = vrtx;
      }
    }

    if (Integer.MAX_VALUE == minLength) {
      commAncestor = -1;
    }

    return commAncestor;
  }
Пример #9
0
  // a common ancestor that participates in shortest ancestral path; -1 if no such path
  public int ancestor(Iterable<Integer> v, Iterable<Integer> w) {
    if (!isValid(v)) {
      throw new java.lang.NullPointerException("Invalid v parameter");
    }

    if (!isValid(w)) {
      throw new java.lang.NullPointerException("Ivalid w parameter");
    }

    int ancestor;
    int len;
    ShortestPath sp;
    ShortestPath maxsp = new ShortestPath();

    maxsp.length = G.V() + 1;
    maxsp.ancestor = -1;

    for (int iv : v) {
      for (int iw : w) {
        sp = findShortestPath(iv, iw);

        if ((sp.length > 0) && (sp.length < maxsp.length)) {
          maxsp.length = sp.length;
          maxsp.length = sp.ancestor;
        }
      }
    }

    return maxsp.ancestor;
  }
Пример #10
0
  private ShortestPath findShortestPath(int v, int w) {
    if (!isValid(v)) {
      throw new java.lang.NullPointerException("Invalid v parameter");
    }

    if (!isValid(w)) {
      throw new java.lang.NullPointerException("Ivalid w parameter");
    }

    Queue<Integer> q = new Queue<Integer>();
    boolean[] marked = new boolean[G.V()];
    int[] distTo = new int[G.V()];

    q.enqueue(v);
    q.enqueue(w);

    marked[v] = true;
    marked[w] = true;
    distTo[v] = 0;
    distTo[w] = 0;

    while (!q.isEmpty()) {
      int a = q.dequeue();
      for (int b : G.adj(a)) {
        if (marked[b]) {
          int length = distTo[b] + distTo[a] + 1;
          ShortestPath sp = new ShortestPath();

          sp.ancestor = b;
          sp.length = length;

          return sp;
        }

        distTo[b] = distTo[a] + 1;
        marked[b] = true;
        q.enqueue(b);
      }
    }

    return null;
  }
Пример #11
0
  // constructor takes the name of the two input files
  public WordNet(String synsets, String hypernyms) {
    ifNullThrowException(synsets);
    ifNullThrowException(hypernyms);

    st = new LinearProbingHashST<String, ArrayList<Integer>>();
    In in = new In(synsets);

    int len = 0;
    int No;
    String[] words;
    ArrayList<String> tempKeys = new ArrayList<String>();
    while (in.hasNextLine()) {
      String[] a = in.readLine().split(",");
      tempKeys.add(a[1]);

      No = Integer.parseInt(a[0]);
      words = a[1].split(" ");
      for (String word : words) {
        if (st.contains(word)) {
          st.get(word).add(No);
        } else {
          ArrayList<Integer> list = new ArrayList<Integer>();
          list.add(No);
          st.put(word, list);
        }
      }
      len++;
    }

    keys = new String[len];
    tempKeys.toArray(keys);

    G = new Digraph(len);
    in = new In(hypernyms);

    while (in.hasNextLine()) {
      String temp = in.readLine();
      String[] a = temp.split(",");
      int v = Integer.parseInt(a[0]);
      for (int i = 1; i < a.length; i++) {
        int w = Integer.parseInt(a[i]);
        G.addEdge(v, w);
      }
    }

    ifNotDagThrowException(G);
    sap = new SAP(G);
  }
Пример #12
0
  private Ancestor computeAncestor(Iterable<Integer> v, Iterable<Integer> w) {
    BreadthFirstDirectedPaths bfsFromV = new BreadthFirstDirectedPaths(digraph, v);
    BreadthFirstDirectedPaths bfsFromW = new BreadthFirstDirectedPaths(digraph, w);

    Ancestor ancestor = new Ancestor();
    ancestor.vertex = -1;
    ancestor.dist = Integer.MAX_VALUE;

    for (int vertex = 0; vertex < digraph.V(); vertex++) {
      if (isAnAncestor(vertex, bfsFromV, bfsFromW)) {
        int distToVertex = bfsFromV.distTo(vertex) + bfsFromW.distTo(vertex);
        if (distToVertex < ancestor.dist) {
          ancestor.vertex = vertex;
          ancestor.dist = distToVertex;
        }
      }
    }
    if (ancestor.dist == Integer.MAX_VALUE) ancestor.dist = -1;
    return ancestor;
  }
Пример #13
0
  public static void main(String[] args) {

    In in1 = new In(Inputs.DIGRAPH_SMALL);
    In in2 = new In(Inputs.DIGRAPH_SMALL);
    edu.princeton.cs.algs4.Digraph sedgewicks = new edu.princeton.cs.algs4.Digraph(in1);
    Digraph digraph = new Digraph(in2);
    in1.close();
    in2.close();

    StdOut.printf("Sedgewicks - v: %d, e: %d\n", sedgewicks.V(), sedgewicks.E());
    for (int i = 0; i < sedgewicks.V(); i++) {
      for (int w : sedgewicks.adj(i)) {
        StdOut.printf("%d -> %d\n", i, w);
      }
    }
    StdOut.println();

    StdOut.printf("My - v: %d, e: %d\n", digraph.V(), digraph.E());
    for (int i = 0; i < digraph.V(); i++) {
      for (int w : digraph.adj(i)) {
        StdOut.printf("%d -> %d\n", i, w);
      }
    }
    StdOut.println();

    edu.princeton.cs.algs4.Digraph sedwickDi = sedgewicks.reverse();
    StdOut.printf("Sedgewicks reverse - v: %d, e: %d\n", sedwickDi.V(), sedwickDi.E());
    for (int i = 0; i < sedwickDi.V(); i++) {
      for (int w : sedwickDi.adj(i)) {
        StdOut.printf("%d -> %d\n", i, w);
      }
    }
    StdOut.println();

    Digraph myReverse = digraph.reverse();
    StdOut.printf("My reverse - v: %d, e: %d\n", myReverse.V(), myReverse.E());
    for (int i = 0; i < myReverse.V(); i++) {
      for (int w : myReverse.adj(i)) {
        StdOut.printf("%d -> %d\n", i, w);
      }
    }
  }
Пример #14
0
 private boolean checkVertexInBound(int vertex) {
   return ((0 <= vertex) && (vertex < copyG.V()));
 }
Пример #15
0
 public UncoverBipartite(Digraph G) {
   this.G = G;
   this.bipartite = new Digraph(G.V() * 2); // for both side of the bigraph
 }