示例#1
0
    /**
     * Initializes a digraph from a file using the specified delimiter.
     * Each line in the file contains
     * the name of a vertex, followed by a list of the names
     * of the vertices adjacent to that vertex, separated by the delimiter.
     * @param filename the name of the file
     * @param delimiter the delimiter between fields
     */
    public SymbolDigraph(String filename, String delimiter) {
        st = new ST<String, Integer>();

        // First pass builds the index by reading strings to associate
        // distinct strings with an index
        In in = new In(filename);
        while (in.hasNextLine()) {
            String[] a = in.readLine().split(delimiter);
            for (int i = 0; i < a.length; i++) {
                if (!st.contains(a[i]))
                    st.put(a[i], st.size());
            }
        }

        // inverted index to get string keys in an aray
        keys = new String[st.size()];
        for (String name : st.keys()) {
            keys[st.get(name)] = name;
        }

        // second pass builds the digraph by connecting first vertex on each
        // line to all others
        G = new Digraph(st.size());
        in = new In(filename);
        while (in.hasNextLine()) {
            String[] a = in.readLine().split(delimiter);
            int v = st.get(a[0]);
            for (int i = 1; i < a.length; i++) {
                int w = st.get(a[i]);
                G.addEdge(v, w);
            }
        }
    }
示例#2
0
 /**
  * Returns the integer associated with the vertex named <tt>s</tt>.
  * @param s the name of a vertex
  * @return the integer (between 0 and <em>V</em> - 1) associated with the vertex named <tt>s</tt>
  */
 public int index(String s) {
     return st.get(s);
 }