list.h

根据潜在语义分析进行查询。将文本中的特征集合做LSI变换。

// Fig. 15.3: list.h
// Template List class definition
#ifndef LIST_H
#define LIST_H

#include <iostream>
#include <cassert>
#include "listnd.h"

//using std::cout;

template< class NODETYPE >
class List {
public:
   List();      // constructor
   ~List();     // destructor
   void insertAtFront( const NODETYPE & );
   void insertAtBack( const NODETYPE & );
   bool removeFromFront( NODETYPE & );
   bool removeFromBack( NODETYPE & );
   int findTerm( const NODETYPE & );
   int find( const NODETYPE & );
   bool isEmpty() const;
   void print() const;
private:
   ListNode< NODETYPE > *firstPtr;  // pointer to first node
   ListNode< NODETYPE > *lastPtr;   // pointer to last node

   // Utility function to allocate a new node
   ListNode< NODETYPE > *getNewNode( const NODETYPE & );
};

// Default constructor
template< class NODETYPE >
List< NODETYPE >::List() : firstPtr( 0 ), lastPtr( 0 ) { }

// Destructor
template< class NODETYPE >
List< NODETYPE >::~List()
{
   if ( !isEmpty() ) {    // List is not empty
      //cout << "Destroying nodes ...\n";

      ListNode< NODETYPE > *currentPtr = firstPtr, *tempPtr;

      while ( currentPtr != 0 ) {  // delete remaining nodes
         tempPtr = currentPtr;
		 //std::cout << tempPtr->data << '\n';
         currentPtr = currentPtr->nextPtr;
         delete tempPtr;
      }
   }

   //cout << "All nodes destroyed\n\n";
}

// Insert a node at the front of the list
template< class NODETYPE >
void List< NODETYPE >::insertAtFront( const NODETYPE &value )
{
   ListNode< NODETYPE > *newPtr = getNewNode( value );

   if ( isEmpty() )  // List is empty
      firstPtr = lastPtr = newPtr;
   else {          // List is not empty
      newPtr->nextPtr = firstPtr;
      firstPtr = newPtr;
   }
}

// Insert a node at the back of the list
template< class NODETYPE >
void List< NODETYPE >::insertAtBack( const NODETYPE &value )
{
   ListNode< NODETYPE > *newPtr = getNewNode( value );

   if ( isEmpty() )  // List is empty
      firstPtr = lastPtr = newPtr;
   else {          // List is not empty
      lastPtr->nextPtr = newPtr;
      lastPtr = newPtr;
   }
}


template< class NODETYPE >
int List< NODETYPE >::findTerm( const NODETYPE &value )
{

   int intCurrentPos = 1;
   ListNode< NODETYPE > *currentPtr = firstPtr;

	String temp2 = value;
	char * temp3 =  temp2.returnChar();//.returnChar();


   while ( currentPtr != 0 ) {
	   char * temp1 =  currentPtr->data.returnChar();
	   
       //cout << "Matching : " << temp1 << " and " << temp3 << endl;
	   if (currentPtr->data == value)
		{
		   //cout << "Found Match at location: " << intCurrentPos << endl;
		   return intCurrentPos;
	   }
	   else
	   {	intCurrentPos++;
			currentPtr = currentPtr->nextPtr; 
	   }
	   
   }
	
   return 0; //no match

}


template< class NODETYPE >
int List< NODETYPE >::find( const NODETYPE &value )
{
   int intCurrentPos = 1;
   ListNode< NODETYPE > *currentPtr = firstPtr;

   while ( currentPtr != 0 ) {
	   if (currentPtr->data == value)
		{
		   return intCurrentPos;
	   }
	   else
	   {	intCurrentPos++;
			currentPtr = currentPtr->nextPtr; 
	   }
	   
   }
	
   return 0; //no match

}


// Delete a node from the front of the list
template< class NODETYPE >
bool List< NODETYPE >::removeFromFront( NODETYPE &value )
{
   if ( isEmpty() )             // List is empty
      return false;             // delete unsuccessful
   else {
      ListNode< NODETYPE > *tempPtr = firstPtr;

      if ( firstPtr == lastPtr )
         firstPtr = lastPtr = 0;
      else
         firstPtr = firstPtr->nextPtr;

      value = tempPtr->data;  // data being removed
      delete tempPtr;
      return true;            // delete successful
   }
}

// Delete a node from the back of the list
template< class NODETYPE >
bool List< NODETYPE >::removeFromBack( NODETYPE &value )
{
   if ( isEmpty() )
      return false;   // delete unsuccessful
   else {
      ListNode< NODETYPE > *tempPtr = lastPtr;

      if ( firstPtr == lastPtr )
         firstPtr = lastPtr = 0;
      else {
         ListNode< NODETYPE > *currentPtr = firstPtr;

         while ( currentPtr->nextPtr != lastPtr )
            currentPtr = currentPtr->nextPtr;

         lastPtr = currentPtr;
         currentPtr->nextPtr = 0;
      }

      value = tempPtr->data;
      delete tempPtr;
      return true;   // delete successful
   }
}

// Is the List empty?
template< class NODETYPE > 
bool List< NODETYPE >::isEmpty() const 
   { return firstPtr == 0; }

// Return a pointer to a newly allocated node
template< class NODETYPE >
ListNode< NODETYPE > *List< NODETYPE >::getNewNode( 
                                        const NODETYPE &value )
{
   ListNode< NODETYPE > *ptr = 
      new ListNode< NODETYPE >( value );
   assert( ptr != 0 );
   return ptr;
}

// Display the contents of the List
template< class NODETYPE >
void List< NODETYPE >::print() const
{
   if ( isEmpty() ) {
      cout << "The list is empty\n\n";
      return;
   }

   ListNode< NODETYPE > *currentPtr = firstPtr;

   cout << "The list is: ";

   while ( currentPtr != 0 ) {
	   std::cout << currentPtr->data << ' ';
      currentPtr = currentPtr->nextPtr;
   }

   cout << "\n\n";
}

#endif


/**************************************************************************
 * (C) Copyright 2000 by Deitel & Associates, Inc. and Prentice Hall.     *
 * All Rights Reserved.                                                   *
 *                                                                        *
 * DISCLAIMER: The authors and publisher of this book have used their     *
 * best efforts in preparing the book. These efforts include the          *
 * development, research, and testing of the theories and programs        *
 * to determine their effectiveness. The authors and publisher make       *
 * no warranty of any kind, expressed or implied, with regard to these    *
 * programs or to the documentation contained in these books. The authors *
 * and publisher shall not be liable in any event for incidental or       *
 * consequential damages in connection with, or arising out of, the       *
 * furnishing, performance, or use of these programs.                     *
 *************************************************************************/