Solution for QID #45819: Course: Data Structure and Algorithm Language: C++ Top | StudyHelpMe

Course: Data Structure and Algorithm Language: C++ Topic: Implementation of Doubly Linked List   Write a simple airline ticket reservation system program. The program should display a menu with following options: Reserve a ticket, cancel a reservation, check whether a ticket is reserved for a particular person and display the passengers. The information is maintained alphabetized link list of names. In a simpler version of the program, assume that tickets are reserved for only one flight. In a fuller version, place no limit on the number of flights. Create link list of flights with each node including a pointer to a link list of passengers. For above Question, Code is given below in Singly Linked List, But I want to convert this code in doubly linked List. Please do this.   NOTE: "It is a complete question. Graph, link or other material etc. are not used and required. I will very Thankful to you if you convert this code in Doubly Linked List."   #include<iostream> #include<string> using namespace std; class Passenger { public:        string Pessenger_Name;        string Flight_Name;        Passenger *next_val;        Passenger(const string a, string b, Passenger* p = NULL)        {               this->Pessenger_Name = a;               this->Flight_Name = b;               this->next_val = p;        } }; class classTicket { private:        Passenger *headval, *tailval; public:        classTicket();        ~classTicket();        void Ticket_reservation();        void cancel_Ticket();        void check_Ticket();        void display(); }; classTicket::classTicket() {        headval = tailval = NULL; } classTicket::~classTicket() {        Passenger* P1 = headval, *q1 = headval;        while (P1 != NULL)        {               q1 = headval->nextval;               delete P1;               P1 = q1;        } } void classTicket::Ticket_reservation() {        string Pessenger_Name, Flight_Name;        cout << "passenger name?" << endl;        cin >> Pessenger_Name;        cout << "flight name?" << endl;        cin >> Flight_Name;        if (headval == NULL)        {               headval = tailval = new Passenger(Pessenger_Name, Flight_Name);               cout << "ticket reserved" << endl;               return;        }        else        {               Passenger *P1 = headval;               while (P1->next_val)               {                      if (Pessenger_Name < P1->Pessenger_Name)                            break;                      else                            P1 = P1->next_val;               }               P1->next_val = new Passenger(Pessenger_Name, Flight_Name, P1->next_val);               cout << "" << endl;               return;        } } void classTicket::cancel_Ticket() {        string Pessenger_Name, Flight_Name;        cout << "passenger name?" << endl;        cin >> Pessenger_Name;        cout << "flight name?" << endl;        cin >> Flight_Name;        Passenger *P1 = headval, *q1 = headval;        if ((Pessenger_Name == Pessenger_Name) && (P1->Flight_Name == Flight_Name))        {               headval = headval->next_val;               cout << "ticket cancelled" << endl;               delete P1;               return;        }        P1 = headval->next_val;        while (P1)        {               if ((P1->Pessenger_Name == Pessenger_Name) && (P1->Flight_Name == Flight_Name))               {                      q1->next_val = P1->next_val;                      delete P1;                      cout << "could not cancelled the ticket?" << endl;                      return;               }               else               {                      q1 = P1;                      P1 = P1->next_val;               }        }        cout << "" << endl;        return; } void classTicket::check_Ticket() {        string Pessenger_Name;        cout << "passenger name" << endl;        cin >> Pessenger_Name;        Passenger* P1 = headval;        while (P1 != NULL)        {               if (P1->Pessenger_Name == Pessenger_Name)               {                      cout << "passenger name?" << P1->Pessenger_Name << endl;                      cout << " flight name" << P1->Flight_Name << endl;                      return;               }               else                      P1 = P1->next_val;        }        cout << "ticket checked" << endl;        return; } void classTicket::display() {        Passenger* P1 = headval;        while (P1 != NULL)        {               cout << "display the passenger" << P1->Pessenger_Name << endl;               cout << " Flight Name:" << P1->Flight_Name << endl;               P1 = P1->next_val;        } } int main() {        classTicket t1;        while (true)        {               cout << "airline ticket reservation" << endl;               cout << "enter the choice" << endl;               cout << "1.For Ticket_reservation" << endl;               cout << "2.For cancel ticket" << endl;               cout << "3.For check ticket" << endl;               cout << "4.For display ticket" << endl;               cout << "5.For end program" << endl;               cout << endl;               int f;               cin >> f;               switch (f)               {               case 1:                      t1.Ticket_reservation();                      break;               case 2:                      t1.cancel_Ticket();                      break;               case 3:                      t1.check_Ticket();                      break;               case 4:                      t1.display();                      break;               case 5:                      return 0;               default:                      cout << "end" << endl;                      break;               }        }        return 0; }