SymbolEWDigraph.java

public class SymbolEWDigraph {
    private ST<String, Integer> st;  // string -> index
    private String[] keys;           // index  -> string
    private EdgeWeightedDigraph G;
    
     public SymbolEWDigraph(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 array
        keys = new String[st.size()];
        for (String name : st.keys()) {
            keys[st.get(name)] = name;
        }
     }
     
     public void createDigraph(String filename, String delimiter, GeoInfo locations) {
        G = new EdgeWeightedDigraph(st.size());
        In 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]);
                double weight = (locations.get(a[0])).distance(locations.get(a[i]));
                G.addEdge(new DirectedEdge(v, w, weight));
            }
        }
    }

    public boolean contains(String s) {
        return st.contains(s);
    }

    public int index(String s) {
        return st.get(s);
    }

    public String name(int v) {
        return keys[v];
    }

    public EdgeWeightedDigraph G() {
        return G;
    }
}