What will be browserhistory.cpp in order for the code to run?

#ifndef browserhistory_h

#define browserhistory_h

#include

#include

using namespace std;

class BrowserHistory

{

private:

// A stack of strings - these are the only variables you need!

// See http://www.cplusplus.com/reference/stack/stack/ for class reference, methods, etc.

stack past;

public:

// Creates a new browser history with only one page visited: default_url

BrowserHistory(string default_url);

// Returns the current page.

string current_url();

// Moves the browser to a new page url via,

// e.g., clicking a link, typing into the address bar, etc.

// so you should add the new link to the stack

void go_to_url(string url);

// Moves back (into the past) by one url.

//

// If there is no past url to move to, does nothing.

void back();

// Returns whether there is a url in the past,

// i.e. whether the back button can be pushed.

// Hint: past.empty() returns a boolean which tell you if the stack is empty or not

bool can_go_back();

// Returns how many urls are in the past,

// i.e. how many times in a row the back button could be pushed.

// check the stack methods and see if there is any method that can help you

int past_url_count();

};

#endif /* browserhistory_h */

main.cpp

#include

#include "browserhistory.h"

int main()

{

// Comments below indicate the current (expected) state of the history.

// Example: [url1, url2, url3, (url4), url5, url6]

// The urls are listed oldest to newest from left to right,

// and the url in parentheses is the current url.

// History: [(google.com)]

BrowserHistory bh("http://google.com");

cout << "Starting at " << bh.current_url() << "." << endl;

cout << "Choose (B)ack, or enter a url to go to." << endl;

string line;

while (cin)

{

string line;

getline(cin, line);

if (line == "B")

{

if (bh.can_go_back())

{

bh.back();

cout << " Now at " << bh.current_url() << endl;

}

else

cout << " Cannot go back." << endl;

}

else if (line.size() > 0)

{

bh.go_to_url(line);

cout << " Now at " << bh.current_url() << endl;

}

}

exit(0);

}