class List;Pretty strait forward. Next. Constructors & Destructor:
class Node{
int _data;
Node* _next; Node* _prev;
Node(int data, Node* next = (Node*)0);
friend class List;
};
class List{
Node* _head;
Node* _tail;
Node* _cur;
public:
List();
...(functions)
virtual ~List();
};
Node::Node(int data, Node* next, Node* prev){
_data = data;
_next = next;
_prev = prev;
etc...
}
Queue::Queue(){
_head = (Node*)0;
}
Queue::~Queue(){
while(!isEmpty()) removeHead();
}Now. After we've covered basics, we should move to functions themselves, and we should start with the most basic function possible "isEmpty" because it's used in most methods.
bool Queue::isEmpty(){
return !_head;
}Nature of a linklist is that if there is nothing at the head, there is nothing in the entire list. So we use it here.
After that, we should add something to the head of the list:
void Queue::add(int data){
if(isEmpty()){
_head = new Node(data);
}else{
Node* cur = _head;
Node* tail = cur;
while(cur){
tail = cur;
cur= cur->_next;
}
tail->_next = new Node(data);
}
}
int Queue::remove(){
int ret = _head->_data;
Node* ToDel = _head;
_head = _head->_next;
delete ToDel;
return ret;
}
This should cover at least most of it.
