数据结构和算法

链表：

package link;

public class Link {

 public int iData;
 public Link next = null;
 public Link(int data) {
  super();
  iData = data;
  next = null;
 }
 
 public void displayLink(){
  System.out.println("Link: {"+iData+"}");
 }
 
 public String toString(){
  return "{"+iData+"}";
 }
  
}

package link;

public class LinkList {

 private Link first;

 public LinkList(Link first) {
  super();
  this.first = first;
 }
 
 public LinkList() {
  this.first = null;
 }
 
 public void insertFirst(int id){
  Link link = new Link(id);
  link.next = first;//the old
  first = link;
  
 }
 
 public Link find(Link key){
  Link k = first;
  while(k != null){
   if(k.iData == key.iData)
    return k;
   k = k.next;
  }
  
  return k;
 }
 
 public boolean delete(Link key){
  if(key == null)
   return false;
  if(find(key) == null)
   return false;
  Link current = first;
  Link pre = first;
  while(current != null){
   if(current.iData == key.iData){
    
    if(current == first){//删除的是第一个元素
     current = current.next;
     pre =  current;
     first = current;
    }else{
     current = current.next;
     pre.next = current;
     
    }
    return true;
   }else{
    pre = current;
    current = current.next;
    
   }
   
  }
  return false;
   
 }
 
 
 public void displayLinkList(){
  System.out.println("LinkList:first --> last");
  Link link = first;
  while(link != null){
   link.displayLink();
   link = link.next;
  }
  
 }
}

 

package link;

public class LinkListApp {

 public static void main(String args[]){
  LinkList link = new LinkList();
  link.insertFirst(3);
  link.insertFirst(31);
  link.insertFirst(2);
  link.insertFirst(12);
  link.insertFirst(1);
  link.insertFirst(11);
  
  link.displayLinkList();
  Link f = new Link(12);
  Link k = link.find(f);
  if(k != null){
   System.out.println("find key"+f);
   k.displayLink();
   
  }else{
   System.out.println("not find key"+f);
  }
  
  boolean a = link.delete(f);
  if(a){
   System.out.println("delete key"+f+":"+a);
   link.displayLinkList();
  }else{
   System.out.println("not delete key"+f+":"+a);
  }
 }
}