Question

// Code is buggy. Fix bugs. Do NOT re-write the whole code!

#include <iostream>

using namespace std;

class LinkedList;

class Node
{
private:
string data;
Node* next;
public:
Node(string s, Node* n);
string getData() {return data;}
Node* getNext() {return next;}
}

Node::Node(string s, Node* n)
{
data = s;
next = n;
}

class LinkedList {
private:
Node* head;
public:
LinkedList();
bool insert(string s);
friend ostream& operator<<(ostream& os, LinkedList l);
};

LinkedList::LinkedList() : head(nullptr)
{ }

bool LinkedList::insert(string s)
{
// Create a node
Node n = new Node(s, head);
head = n;
}

ostream& operator<<(ostream& os, LinkedList l)
{
Node* n = l->head;
while (n == nullptr) {
os << n->getData() << " ";
n = n->getNext();
}

}

int main()
{
LinkedList poets;
poets.insert("Wordsworth");
poets.insert("Shelley");
poets.insert("Byron");
cout << poets << endl; //Should print Byron Shelley Wordsworth
  
}

Answer 1

#include <iostream>

using namespace std;

//class LinkedList;//removed

class Node
{
public:
string data;
Node* next;
public:
Node(string s, Node* n);
string getData() {return data;}
Node* getNext() {return next;}
};//semicolon added here

Node::Node(string s, Node* n)
{
data = s;
next = n;
}

class LinkedList {
public://modified
Node* head;
public:
LinkedList();
bool insert(string s);
friend ostream& operator<<(ostream& os, LinkedList *l);
};

LinkedList::LinkedList() //: head(nullptr)
{
   head=NULL;
}

bool LinkedList::insert(string s)
{
// Create a node
Node *n = new Node(s, head);//modified
head = n;
}

ostream& operator<<(ostream& os, LinkedList *l)//modified
{

Node* n = l->head;
while (n != NULL) //modified
{

os << n->getData() << " ";
n = n->getNext();
}

}

int main()
{
LinkedList *poets= new LinkedList();
poets->insert("Wordsworth");
poets->insert("Shelley");
poets->insert("Byron");
cout << poets<<endl; //Should print Byron Shelley Wordsworth
return 0;
}

output:

Byron Shelley Wordsworth

Process exited with return value 3221225477
Press any key to continue . . .