link.java

寻找最短路径A_算法的实现

/*
 * Link.java
 *
 * Created on 2004年9月24日, 下午8:45
 */

/**
 *
 * @author  xhuad
 */
import java.util.Vector;
public class Link {
    private Vector link = new Vector();
   // private Link next = null;
    public Link() {        
    }
    
    public boolean addNode(Node setNode){//增加一个节点
        setNode = checkNode(setNode);
        if(setNode != null){                 
            this.link.addElement((Node)setNode);            
            return true;
        }
        return false;
    }
    
    public void delNode(Node setNode){ //删除一个节点        
        if(!this.link.isEmpty()){                         
            for(int i=0;i < this.link.size(); i++)
            {
                if(setNode.getPos() == ((Node)this.link.elementAt(i)).getPos()){
                    this.link.remove(i);
                    //System.out.println("asdfasdfas:"+this.link.size());
                    break;
                }
            }                        
        }
    }    
    
 
    public Node checkNode(Node setNode){//判断节点是否在链表里面并取得两者的最佳值
        if(!this.link.isEmpty() && setNode!=null){                         
            for(int i=0;i < this.link.size(); i++)
            {
                if(setNode.getPos() == ((Node)this.link.elementAt(i)).getPos()){
                    if(setNode.getStep() < ((Node)this.link.elementAt(i)).getStep()){
                        setNode = (Node)this.link.elementAt(i);
                        this.link.remove(i);
                    }
                    else
                        return null;
                    break;
                }                
            }                        
        }
        return setNode;        
    }
    
    public boolean isEmpty(){
        return this.link.isEmpty();
    }
    
    public Node getBestNode(){ //得到最好的节点
        Node tmpNode = null;
        if(!this.link.isEmpty()){
            tmpNode = (Node)this.link.elementAt(0);              
            //System.out.println("tmpNodeStep:"+tmpNode.getStep());
            //System.out.print("OpenNode(pos,step):");
            for(int i=1;i < this.link.size(); i++)
            {
                //System.out.print("("+((Node)this.link.elementAt(i)).getPos()+","+((Node)this.link.elementAt(i)).getStep()+")");
                if(tmpNode.getJudgeNum() >= ((Node)this.link.elementAt(i)).getJudgeNum()){
                    tmpNode = (Node)this.link.elementAt(i);                          
                }                
            }               
        }
        return tmpNode;
    }    
    
}