1. (20%) 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. (a) 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 (b) 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. (e) Write a Forward and a Backward function to traverse the browsing history and return the URL of the new current page. (d) Provide a Display function to print out the entire browsing history (e) Test your functions properly in the main program