[자료구조(Data Structure)] - 4. Circular Linked List - Java

[자료구조(Data Structure)] - 4. Circular Linked List - Java

 

작년에 배운 자료구조 복습 겸 다시 짜봤습니다.

LinkedList Class 내에 headnode와 firstnode를 보통은 두고 짜는 데 한번 rootnode 하나만 두고 대신 length(정수형)을 추가하여 구현해봤습니다.

 

전체 로직은 이렇습니다.

 

 

/*              Data Structure Circular Linked List - rootnode만 이용        2015. 4. 25        James */    class Node {         private Object data;         private Node prev;         private Node next;           // Getter         public Object getdata()         {              return this.data;         }         public Node getprev()         {              return this.prev;         }         public Node getnext()         {               return this.next;         }           // Setter         public void setdata(Object data)        {              this.data = data;        }        public void setprev(Node prev)        {              this.prev = prev;        }        public void setnext(Node next)        {              this.next = next;        } }  class LinkedList{        private Node headnode;        private long length;          public LinkedList(){               this.headnode = null;               this.length = 0;        }        public void insert(Object data)        {               Node createnode = new Node();                 createnode.setdata(data);               createnode.setprev( createnode );               createnode.setnext( createnode );                  if ( this.headnode == null )               {                        this.headnode = createnode;               }               else               {                        Node firstnode = this.headnode.getnext();                              // 현재 기억하고 있는 이전 노드 설정                       createnode.setprev ( this.headnode );                       // 맨 마지막 노드 처음 위치 지정                       createnode.setnext ( firstnode );                       // 현재 노드 -> node 삽입 (Next)                       this.headnode.setnext( createnode );                           // 현재 노드 -> 다음 노드로 이동                       this.headnode = this.headnode.getnext();                       // 맨 처음 노드 마지막 위치 지정                       firstnode.setprev( this.headnode );               }               this.length++;     }    public void remove(Object data)  {              Node currentnode = this.headnode.getnext();              boolean check = false;                long cnt = 0;                   // 데이터 검색              while ( cnt < length )              {                        if( currentnode.getdata() == data)                        {                                    check = true;                                break;                        }                        currentnode = currentnode.getnext();                            cnt++;              }                 // 3가지 기준 (맨 처음 자료, 중간 자료, 맨 마지막 자료)               if ( check == true )               {                       Node firstnode = this.headnode.getnext();                       Node lastnode = this.headnode;                          // 맨 처음 자료                       if ( currentnode == firstnode )                       {                                  // 다음 주소가 firstnode와 일치시                                 if ( this.headnode.getnext ( ) == firstnode ){                                         Node prevnode = firstnode.getprev();                                         Node nextnode = firstnode.getnext();                                               firstnode = nextnode;                                         firstnode.setprev ( prevnode ) ;                                         this.headnode.setnext ( firstnode ) ;                                }                                else                                         this.headnode = this.headnode.getnext ( ) ;                        }                        // 중간 자료 판별                      if ( currentnode != firstnode && currentnode != lastnode )                      {                                Node prevnode = currentnode.getprev ( ) ;                                Node nextnode = currentnode.getnext ( ) ;                                currentnode = prevnode ;                                currentnode.setnext ( nextnode ) ;                                nextnode.setprev ( prevnode );                       }                         // 마지막 자료 판별                       if ( currentnode == lastnode && this.headnode != null )                       {                                Node prevnode = currentnode.getprev ( ) ;                                                         prevnode.setnext ( firstnode ) ;                                firstnode.setprev ( prevnode ) ;                                      currentnode = null ;                                this.headnode = prevnode;                       }                         this.length--;                 }           }            public void view()         {                   Node currentnode = this.headnode.getnext();                        long cnt = 1;                   while ( cnt <= length )                   {                            System.out.println( "번호:" + cnt + ", Data:" + currentnode.getdata() ) ;                                currentnode = currentnode.getprev() ;                            cnt++;                   }           }            public long getlength()          {                   return this.length;          }             public Node getnode()           {                   return this.headnode;           } }   public class Ds{          public static void main(String args[])         {              LinkedList list = new LinkedList();              list.insert("야호1");               list.view();              list.remove("야호1");              System.out.println( list.getlength() ) ;              list.view();        } }

Ds.java