vertex.java

"java数据结构与算法" 书中的源代码

package dsa.adt;


public class Vertex {
	private Object info;		//顶点信息
	private LinkedList adjacentEdges;	//顶点的邻接边表
	private LinkedList reAdjacentEdges;	//顶点的逆邻接边表，无向图时为空
	private boolean visited;	//访问状态
	private Node vexPosition;	//顶点在顶点表中的位置
	private int graphType;		//顶点所在图的类型
	private Object application;	//应用信息。例如求最短路径时为Path，求关键路径时为Vtime
	//构造方法:在图G中引入一个新顶点
	public Vertex(Graph g, Object info) {
		this.info = info;
		adjacentEdges = new LinkedListDLNode();
		reAdjacentEdges = new LinkedListDLNode();
		visited = false;
		graphType = g.getType();
		vexPosition = g.insert(this);
		application = null;
	}
	//辅助方法:判断顶点所在图的类型
	private boolean isUnDiGraphNode(){ return graphType==Graph.UndirectedGraph;}
	
	//获取或设置顶点信息
	public Object getInfo(){ return info;}
	public void setInfo(Object obj){ this.info = info;}
	
	//与顶点的度相关的方法
	public int getDeg(){
		if (isUnDiGraphNode())
			return adjacentEdges.getSize();	//无向图顶点的(出/入)度即为邻接边表的规模
		else
			return getOutDeg()+getInDeg();	//有向图顶点的度为出度与入度之和
	}
	public int getOutDeg(){ 
		return adjacentEdges.getSize();		//有(无)向图顶点的出度为邻接表规模
	}
	public int getInDeg(){
		if (isUnDiGraphNode())
			return adjacentEdges.getSize();	//无向图顶点的入度就是它的度
		else
			return reAdjacentEdges.getSize();//有向图顶点入度为逆邻接表的规模
	}
	
	//获取与顶点关联的边
	public LinkedList getAdjacentEdges(){ return adjacentEdges;}
	public LinkedList getReAdjacentEdges(){
		if (isUnDiGraphNode())
			return adjacentEdges;	//无向图顶点无逆邻接边表,其逆邻接边表就是邻接边表
		else
			return reAdjacentEdges;
	}
	
	//取顶点在所属图顶点集中的位置
	public Node getVexPosition(){ return vexPosition;}

	//与顶点访问状态相关方法
	public boolean isVisited(){ return visited;}
	public void setToVisited(){ visited = true;}
	public void setToUnvisited(){ visited = false;}
	
	//取或设置顶点应用信息
	protected Object getAppObj(){ return application;}
	protected void setAppObj(Object app){ application = app;}
	
	//重置顶点状态信息
	public void resetStatus(){
		visited = false;
		application = null;
	}
}