Friday, March 29, 2013

DLL Template (dll.h) and dllTester.cpp

#ifndef __CC_DLL_H_
#define __CC_DLL_H_
#include <iostream>
using namespace std;

template <class T>
class DLL;

template <class T>
class Node{
  T _data;
  Node<T>* _prev;
  Node<T>* _next;
  Node(T data, Node<T>* prev=(Node<T>*)0, Node<T>* next=(Node<T>*)0);// just incase, review later
  friend class DLL<T>;
};

template <class T>
class DLL{
  Node<T>* _head;
  Node<T>* _curr;
  Node<T>* _tail;
  void copy(DLL<T>& D);
public:
  DLL();
  DLL(DLL<T>& D);
  virtual ~DLL();
  bool isEmpty();
  void append(T data);
  DLL<T>& operator=(DLL<T>& D);
  T remove();   // removes the current node and returns the data
  bool del();     // removes the current node returns false if is empty
  void insert(T data); // insterts before current
  bool goHead();
  bool goTail();
  bool goNext();
  bool goPrev();
  T visit();    // returns the current data
  int dept() const; // returns the number of Nodes
};

template <class T>
Node<T>::Node(T data, Node<T>* prev, Node<T>* next){
  _data = data;
  _prev = prev;
  _next = next;
}

template <class T>
DLL<T>::DLL(){
  _head = _tail = _curr = 0;
}

template <class T>
DLL<T>::~DLL(){
  while(del());
}

template <class T>
void DLL<T>::copy(DLL<T>& D){
  int curpos;
  for(curpos=0;D.goPrev();curpos++); // findout where is current
  if(!D.isEmpty()){
    do{
      this->append(D.visit());
    }while(D.goNext());
  }
  for(D.goHead(), this->goHead(); curpos; D.goNext(), this->goNext(),curpos--);
}

template <class T>
DLL<T>::DLL(DLL<T>& D){
  _head = _tail = _curr = 0;
  this->copy(D);
}

template <class T>
DLL<T>& DLL<T>::operator=(DLL<T>& D){
  while(del());
  this->copy(D);
  return *this;
}

template <class T>
void DLL<T>::append(T data){
  Node<T>* newnode = new Node<T>(data);
  if(_tail){  // ! empty
    _tail->_next = newnode;
    newnode->_prev = _tail;
    _tail = _curr = newnode;
  }
  else{
    _tail = _curr = _head = newnode;
  }

}

template <class T>
T DLL<T>::remove(){
  T data = visit();
  del();
  return data;
}

template <class T>
bool DLL<T>::del(){
  bool ok = false;
  if(_curr){
    ok = true;
    Node<T>* todel = _curr;
    (_curr->_next) ? _curr->_next->_prev = _curr->_prev : _tail = _tail->_prev;
    (_curr->_prev) ? _curr->_prev->_next = _curr->_next : _head = _head->_next;
    (_curr->_next) ? _curr = _curr->_next : _curr = _curr->_prev;
    delete todel;
  }
  return ok;
}

template <class T>
void DLL<T>::insert(T data){
    Node<T>* toInsert = new Node<T>(data);
    (_curr->_prev) ? (_curr->_prev->_next = toInsert) : (_head = toInsert);
    toInsert->_prev = _curr->_prev;
    toInsert->_next = _curr;
    _curr->_prev = toInsert;
    _curr = toInsert;
    
}

template <class T>
T DLL<T>::visit(){               // retruns data of current
    return _curr->_data;
}

template <class T>
bool DLL<T>::goHead(){
    return ((_head) && (_curr = _head)) ? true : false;
}

template <class T>
bool DLL<T>::goTail(){
    return ((_tail) && (_curr = _tail)) ? true : false;
}

template <class T>
bool DLL<T>::goNext(){
    return ((_curr->_next) && (_curr = _curr->_next)) ? true : false;
}

template <class T>
bool DLL<T>::goPrev(){
    return ((_curr->_prev) && (_curr = _curr->_prev)) ? true : false;
}

template <class T>
bool DLL<T>::isEmpty(){
    return !_curr;
}

template <class T>
void printList(DLL<T>& d){
    d.goHead();
}

template <class T>
ostream& operator<<(ostream& os, DLL<T>& d){
  int cur;
  bool done = false;
  for(cur=0;d.goPrev();cur++); // findout where is current
  do{
    os<<d.visit();
    done = !d.goNext();
    if(!done){
      os<<", ";
    }
  }while(!done);
  for(d.goHead();cur;d.goNext(), cur--); // set current to what it was before
  return os;
}

template <class T>
ostream& operator>>(ostream& os, DLL<T>& d){ // printing in reverse!!!!!
  int cur;
  bool done = false;
  for(cur=0;d.goNext();cur++); // findout where is current
  do{
    os<<d.visit();
    done = !d.goPrev();
    if(!done){
      os<<", ";
    }
  }while(!done);
  for(d.goTail();cur;d.goPrev(), cur--); // set current to what it was before
  return os;
}
#endif





#include "dll.h"

int main(){
  DLL<int> d;
  for(int i=0;i<10;i++){
    d.append(i+1);
  }
  cout<<d<<endl;
  d.goHead();
  d.insert(1000);
  d.goNext();
  d.insert(2000);
  cout<<d<<endl;
  cout>>d<<endl;
  cout<<d.remove()<<endl;
  cout<<d<<endl;
  return 0;
}

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