#include "MyLinkedBag.h"
//#include <cstddef>
//using namespace std;

  // Constructor  
  MyLinkedBag::MyLinkedBag() : head(NULL) 
  {  
  }

  // Destructor
  MyLinkedBag::~MyLinkedBag() 
  {
      while( head!=NULL ) {
          BagNode *hold = head->next;
          delete head;
          head = hold;
      }
  }          

  // Mutator methods:
  void MyLinkedBag::add(ListType x)   // adds at front
  {
      BagNode *newPtr = new BagNode; 
      newPtr->data = x;
      newPtr->next = head;
      head = newPtr;
  }

  bool MyLinkedBag::remove(ListType x) 
  {
      if( head==NULL )
          return false;
      if( head->data==x ) {
          BagNode *hold = head;
          delete head;
          head = hold;
          return true;
      }
      // so list not empty and not first node to be deleted
      BagNode *cursor = head;
      while( cursor->next != NULL  &&  cursor->next->data != x )
          cursor = cursor->next;
      if(cursor->next == NULL)
          return false;
      else {
          BagNode *hold = cursor->next->next;
          delete ( cursor->next );
          cursor->next = hold;
          return true;
      }
  }

  // Accessor methods:
  bool MyLinkedBag::isEmpty() const   // Returns: whether the list is empty.
  {
      return (head==NULL);
  }

  ostream & operator<< ( ostream & out, const MyLinkedBag & other)
  {
      for(  BagNode *cursor = other.head; cursor; cursor=cursor->next)
          out << cursor->data << " ";
      out << endl;
  }