The most frequently used buttons in a browser are the forwar

The most frequently used buttons in a browser are the forward and backward buttons to traverse the URLs visited by the user. Based on the doubly linked lists data structure, write a C++ program to maintain the browsing history in the following ways. Design a class BrowsingHistory to maintain the browsing history of a user. Each node should store the URL (string) of a web page. The links of a node represent the previous and next page visited by the user. Write a CurrentPage function to return the URL of the current web page under browsing. Also provide a NewPage function to add a new URL into the history. Write a Forward and a Backward function to traverse the browsing history and return the URL of the new current page. Provide a Display function to print out the entire browsing history. Test your functions properly in the main program.

Solution

PROGRAM CODE:

#include <iostream>
using namespace std;

class BrowsingHistory
{
private:
   string URL;
   BrowsingHistory *next;  
   BrowsingHistory *prev;  
public:
   BrowsingHistory()
   {
       URL = \"\";
       next = NULL;
       prev = NULL;
   }
   BrowsingHistory(string url)
   {
       URL = url;
       next = NULL;
       prev = NULL;
   }
   BrowsingHistory(BrowsingHistory *bh)
   {
       URL = bh->URL;
       next = bh->next;
       prev = bh->prev;
   }
   string currentPage()
   {
       return URL;
   }
   void newPage()
   {
       cout<<\"Enter the next address: \";
       string nexturl;
       cin>>nexturl;
       next = new BrowsingHistory(nexturl);
       prev = new BrowsingHistory(this);
       next->next = new BrowsingHistory(\"End of history\");
   }
   string forward()
   {
       BrowsingHistory current = this;
       this->URL = current.next->URL;
       this->next = current.next->next;
       this->prev = &current;
       return this->URL;
  
   }
   string backward()
   {
       if(prev == NULL)
           return \"Beginning of history\";
       else
       {
           BrowsingHistory previous = this->prev;
           BrowsingHistory current = this;
           this->URL = previous.URL;
           this->next = &current;
           this->prev = previous.prev;
           return this->URL;
       }
          
   }
   void display()
   {
       cout<<\"\ Browsing History: \"<<endl;
       BrowsingHistory current = this;
       while(current.prev != NULL)
       {
           current = current.prev;
       }
       while(current.URL != \"End of history\")
       {
           cout<<current.URL<<endl;
           current = current.next;
       }
   }
}*his;

int main() {
   his = new BrowsingHistory(\"www.google.com\");
   cout<<\"Current Page: \"<<his->currentPage()<<\"\ \";
   his->newPage();
   cout<<\"\ Current Page: \"<<his->currentPage()<<\"\ \";
   cout<<\"\ Going forward: \"<<his->forward();
   cout<<\"\ Going backward: \"<<his->backward();
   cout<<\"\ Displaying the history\"<<endl;
   his->display();
   return 0;
}

OUTPUT: