Question

在创建顶点并在定向图中使用它们时遇到一些麻烦。

我有两个要关注的类：Node.java和Digraph.java

  public class Node {
   private final int vertex;
   private HashSet<Node> outgoingEdges;

   public Node(int index) {
    this.index = index;
  }

  protected void addOutgoing(Node start) {
    outgoingEdges.add(start);
}

 public class Digraph {
 private Set<Node> vertices;

 public Digraph(String str) {
 String eliminatePrefix = str.replaceAll("a", "");
 for (int i = 0; i < eliminatePrefix.length; i++) {
     // Not sure how to proceed
     // 
 }

 protected void add(Node a, Node b) {
     a.addOutgoing(b);
 }

传入的字符串看起来像[a1，a2] [a16，a10] .... a1和a2是顶点。配对意味着有从a1到a2的有向路线。我知道，字符串需要被解析和转换，一旦格式正确，就会调用addEdge方法。我只想弄清楚这个构造函数。

Answer 1

也许不是最干净的方法，但它有效

        String s = "[a1, a2][a3, a4][a5, a6]";

    s = s.replaceAll("[a\\s\\[]", ""); // remove " " "[" and ","
    String[] edges = s.split("]"); // split the string into substrings on ]

    for (String edge : edges) {
        String[] points = edge.split(","); 
        int[] p = new int[2];
        p[0] = Integer.parseInt(points[0]);
        p[1] = Integer.parseInt(points[1]);

        // Construct your edge here
        System.out.println("Edge from: " + p[0] + " to " + p[1]);
    }

转换为String传递给Vertex for DirectedGraph

1 个答案: