Java data structure and algorithms note-ch5-List-5 using a double-ended list to implement the queue

1 //implementing queues with a double-ended linked list2 /**3 * Node class4  */5 classLINKQ {6     Private Longdata;7      PublicLINKQ Next;8 9      PublicLINKQ (Longd) {Ten          This. data =D; One     } A  -      PublicString toString () { -         returnString.valueof ( This. data); the     } - } - /** - * Double-ended linked list class +  */ - classFirstlastlink { +     PrivateLINKQ first; A     PrivateLINKQ last; at  -      PublicFirstlastlink () { -First =NULL; -Last =NULL; -     } -  in      Public BooleanIsEmpty () { -         returnFirst = =NULL; to     } +  -      Public voidInsertlast (linkq l) { the         if(IsEmpty ()) *First =l; $         ElsePanax NotoginsengLast.next =l; -Last =l; the     } +  A      PublicLINKQ Deletefirst () { theLINKQ temp =First ; +         if(First.next = =NULL) -Last =NULL; $First =First.next; $         returntemp; -     } -  the @Override -      PublicString toString () {Wuyi         if(IsEmpty ()) the             return"[]"; -LINKQ Curr =First ; WuStringBuilder SB =NewStringBuilder (); -Sb.append ("["); About          while(Curr! =NULL) { $Sb.append (Curr.tostring ()). Append (","); -Curr =Curr.next; -         } -Sb.deletecharat (Sb.length ()-1); ASb.append ("]"); +         returnsb.tostring (); the     } -  $      Public voiddisplay () { the System.out.println (toString ()); the     } the } the /** - * Queue class in * Like the implementation of the Stack class in the previous example, the emphasis is on conceptual entities, independent of their specific implementations.  the * The stack and queue are the same with arrays or linked lists. The importance of the stack is its push pop operations and how they are used; the importance of the queue is removed from the team head, inserted from the end of the team, and how to use it.  the * The intrinsic mechanism for implementing these operations is, in fact, unimportant in its importance.  About  */ the classlinkqueue{ the     PrivateFirstlastlink link; the      PublicLinkqueue () { +link =NewFirstlastlink (); -     } the      Public BooleanIsEmpty () {Bayi         return  This. Link.isempty (); the     } the      Public voidInsert (linkq l) { -          This. Link.insertlast (l); -     } the      Publiclinkq Remove () { the         return  This. Link.deletefirst (); the     } the      PublicString toString () { -         return  This. link.tostring (); the     } the      Public voiddisplay () { the System.out.println (toString ());94     } the } the  Public classLinkqueuedemo { the      Public Static voidMain (string[] args) {98Linkqueue queue =Newlinkqueue (); About          for(inti = 0; I < 5; i++) { -LINKQ l=NewLINKQ (i);101 Queue.insert (l);102 Queue.display ();103         }104          while(!Queue.isempty ()) { theSystem.out.print ("remove element:" +Queue.remove ());106System.out.print (". Now queue is:");107 Queue.display ();108         }109     } the}

Java data structure and algorithms note-ch5-List-5 using a double-ended list to implement the queue