#include using namespace std; struct node { int ch; int data; struct node *next; struct node *prev; }*head; class clsLL { public: struct node *createNode(); void accept(); void display(); void insertAtBeg(); void insertAfter(); void insertAtEnd(); void delAtBeg(); void delAfter(); void delAtEnd(); void search(); void update(); void reverse(); }; //end of class struct node * clsLL::createNode() { struct node *newNode=new node; cout<<"Enter data"; cin>>newNode->data; newNode->next=NULL; newNode->prev=NULL; return(newNode); } void clsLL:: accept() // { struct node *temp; int ch; int n=0; cout<<"how many nodes u want to enter"; cin>>n; for(int i=0;inext != NULL ) { temp = temp->next; } temp->next = newNode; newNode->prev=temp; //line for dll only } //else }//end of for }//end of accept void clsLL ::display() //same as sll { struct node *temp; temp=head; while(temp!=NULL) { cout<data<<"\t"; temp = temp->next; } } void clsLL::insertAtBeg() { struct node *temp; struct node *newNode=createNode(); newNode->next=head; head->prev=newNode;//extra line only for dll head=newNode; cout<<"Node inserted successfully"; } void clsLL:: insertAfter() { int num; struct node *temp,*temp1,*temp2; cout<<"\nEnter The Element After Want to Insert The Node :"; cin>>num; struct node *newNode=createNode(); temp = head; while( temp->data!=num ) { temp=temp->next; } temp1=temp->next; //-------------------20 to 25 temp->next=newNode; newNode->prev=temp; //only for dll //--------------------- 25 to 30 newNode->next=temp1; temp1->prev=newNode;//only for dll cout<<"node inserted successfully"; } void clsLL::insertAtEnd() { struct node *newNode=createNode(); struct node *temp=head; while(temp->next!=NULL) { temp=temp->next; } temp->next=newNode; newNode->prev=temp; //only for dll }//end of insertAtEnd void clsLL:: delAtBeg() { struct node *temp; temp = head; head = head->next; delete temp; cout<<"element deleted successfully"; } void clsLL:: delAfter() { struct node *temp,*temp1,*temp2; int delNo; temp=head; cout<<"\nEnter the data of the node you want to delete: "; cin>>delNo; while(temp->data!=delNo) { temp=temp->next; } //10 20 30 40 50 delete after 30 ie 40 set temp at 30.temp at 40,temp2 at 50 //pointer setting temp1=temp->next; temp2=temp1->next; //connections temp->next=temp2; // 30 to 50 temp2->prev=temp; //50 to 30 temp1->next=NULL; delete temp1; cout<<"node deleted successfully"; } //end of delete after fuction void clsLL:: delAtEnd() { struct node *temp,*old; temp=head; if(temp==NULL) { cout<<"\nThe Linked List is empty"; } else //10 20 30 40,delete 40,temp 40 old at 30 { while(temp->next!=NULL) { //no need to maintain old here temp=temp->next; } old=temp->prev;//make connec null old->next=NULL; temp->prev=NULL; delete temp; cout<<"Node deleted successfully"; } }//end of delete at end function void clsLL::search() //same for all { node *temp; int flag=0,serNo; temp = head; cout<<"\nEnter the element which you want to search : "; cin>>serNo;; while ( temp != NULL ) { if ( temp->data == serNo ) { flag = 1; break; } else { temp = temp->next; } }//end of while if ( flag == 1 ) { cout<<"\n\nThe Element is found ..."; } else { cout<<"\n\nThe Element is not found in the list...."; } }//end of search function void clsLL::update() //same for all { node *temp; int flag=0,serNo; temp = head; cout<<"\nEnter the element which you want to update: "; cin>>serNo; while ( temp != NULL ) { if ( temp->data == serNo ) { cout<<"Enter new Data"; cin>>temp->data; flag = 1; break; } else { temp = temp->next; } }//end of while if ( flag == 1 ) { cout<<"\nThe Element is found and updated successfully.\n"; display(); } else { cout<<"\nThe Element is not found for updation.\n"; } }//end of search function void clsLL:: reverse() //logical reverse //simple just forward and backward { struct node *temp; temp=head; //take list 10 20 30 40 while( temp->next != NULL ) { temp=temp->next; } //print last node i.e 40 cout<data<<"\t"; //now print rev order by prev pointer while(temp->prev!=head) { temp=temp->prev; cout<data<<"\t"; } //print head data cout<data; } int main() { int ch; char resp; clsLL obj; obj.accept(); obj.display(); do { cout<<"\nOperations on Linked List:"; cout<<"\n1.Insert At Begining"; cout<<"\n2.Insert Afer"; cout<<"\n3.Insert at End"; cout<<"\n4.Delete At Beg"; cout<<"\n5.Delete After"; cout<<"\n6. Delete At End"; cout<<"\n7 Search:"; cout<<"\n8 Update "; cout<<"\n9 Reverse"; cout<<"\n10 Exit."; cout<<"\n Plz enter your choice"; cin>>ch; switch(ch) { case 1:obj.insertAtBeg(); obj.display(); break; case 2:obj.insertAfter(); obj.display(); break; case 3:obj.insertAtEnd(); obj.display(); break; case 4:obj.delAtBeg(); obj.display(); break; case 5:obj.delAfter(); obj.display(); break; case 6:obj.delAtEnd(); obj.display(); break; case 7: obj.search(); break; case 8:obj.update(); break; case 9:obj.reverse(); //dont call display function here break; default: cout<<"\nplz enter correct choice"; }//end of swith cout<<"\nDo uwant to continue"; cin>>resp; } while(resp=='y'||resp=='Y'); //end of while return(0); }

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