我想要一个带有“自定义”顶点和边缘的DirectedWeightedMultigraph。 使用此代码,我想只有三个顶点,因为v1和v4具有相同的键,但我有四个。
DirectedWeightedMultigraph<Vertex, Edge> graph = new DirectedWeightedMultigraph<Vertex, Edge>(Edge.class);
Vertex v1 = new Vertex("a", "o1");
Vertex v2 = new Vertex("b", "o2");
Vertex v3 = new Vertex("c", "o1");
Vertex v4 = new Vertex("a", "o3");
graph.addVertex(v1);
graph.addVertex(v2);
graph.addVertex(v3);
graph.addVertex(v4);
System.out.println("#vertex: "+ graph.vertexSet().size());
这就是我的顶点的样子:
public class Vertex {
String key;
String other;
public Vertex(String id, String o){
key = id;
other = o;
}
public boolean equals(Object object) {
if (object == null || !(object instanceof Vertex)) {
return false;
}
return (this.key == ((Vertex) object).key);
}
public boolean isAVertex(Set<Vertex> set) {
boolean result = false;
for (Vertex v : set) {
if (this.equals(v)) {
result = true;
break;
}
}
return result;
}
}
我的边缘看起来像
public class Edge {
int cost;
}
在使用边缘之前,我阅读了关于equals的this和this以及关于顶点和边缘的hashCode。我也尝试使用ParanoidGraph,但它不起作用。为了解决这个问题,我选择“手动”检查在添加顶点之前具有特定键的顶点是否在顶点集中。但我想念我的代码中的错误。我还有四个顶点:
List<Vertex> rowVertices = new ArrayList<Vertex>();
rowVertices.add(v1);
rowVertices.add(v2);
rowVertices.add(v3);
rowVertices.add(v4);
Iterator it = rowVertices.iterator();
while (it.hasNext()) {
Vertex currentVertex = (Vertex) it.next();
if (!currentVertex.isAVertex(graph.vertexSet())) {
graph.addVertex(currentVertex);
}
}
System.out.println("#vertex: "+ graph.vertexSet().size());