DEAR All;
Hi, I'm just beginner to C++; Please help me to understand:
What functions should be in the Linked list class ? I think there should be overloaded operators << and >>; Please help me to improve the code (style, errors, etc,) Thanks for advance. Igal.
Edit: This is only first stage, the next one will be (hopefully) with templates.
Please review the small code for the integer List (enclosed MyNODE.h and ListDriver1.cpp); MyNODE.h
// This is my first attempt to write linked list. Igal Spector, June 2010.
#include <iostream.h>
#include <assert.h>
//Forward Declaration of the classes:
class ListNode;
class TheLinkedlist;
// Definition of the node (WITH IMPLEMENTATION !!!, without test drive):
class ListNode{
friend class TheLinkedlist;
public:
// constructor:
ListNode(const int& value, ListNode *next= 0);
// note: no destructor, as this handled by TheLinkedList class.
// accessor: return data in the node.
// int Show() const {return theData;}
private:
int theData; //the Data
ListNode* theNext; //points to the next node in the list.
};
//Implementations:
//constructor:
inline ListNode::ListNode(const int &value,ListNode *next)
:theData(value),theNext(next){}
//end of ListNode class, now for the LL class:
class TheLinkedlist
{
public:
//constructors:
TheLinkedlist();
virtual ~TheLinkedlist();
// Accessors:
void InsertAtFront(const &);
void AppendAtBack(const &);
// void InOrderInsert(const &);
bool IsEmpty()const;//predicate function
void Print() const;
private:
ListNode * Head; //pointer to first node
ListNode * Tail; //pointer to last node.
};
//Implementation:
//Default constructor
inline TheLinkedlist::TheLinkedlist():Head(0),Tail(0) {}
//Destructor
inline TheLinkedlist::~TheLinkedlist(){
if(!IsEmpty()){ //list is not empty
cout<<"\n\tDestroying Nodes"<<endl;
ListNode *currentPointer=Head, *tempPtr;
while(currentPointer != 0){ //Delete remaining Nodes.
tempPtr=currentPointer;
cout<<"The node: "<<tempPtr->theData <<" is Destroyed."<<endl<<endl;
currentPointer=currentPointer->theNext;
delete tempPtr;
}
Head=Tail = 0; //don't forget this, as it may be checked one day.
}
}
//Insert the Node to the beginning of the list:
void TheLinkedlist::InsertAtFront(const int& value){
ListNode *newPtr = new ListNode(value,Head);
assert(newPtr!=0);
if(IsEmpty()) //list is empty
Head = Tail = newPtr;
else { //list is NOT empty
newPtr->theNext = Head;
Head = newPtr;
}
}
//Insert the Node to the beginning of the list:
void TheLinkedlist::AppendAtBack(const int& value){
ListNode *newPtr = new ListNode(value, NULL);
assert(newPtr!=0);
if(IsEmpty()) //list is empty
Head = Tail = newPtr;
else { //list is NOT empty
Tail->theNext = newPtr;
Tail = newPtr;
}
}
//is the list empty?
inline bool TheLinkedlist::IsEmpty() const
{ return (Head == 0); }
// Display the contents of the list
void TheLinkedlist::Print()const{
if ( IsEmpty() ){
cout << "\n\t The list is empty!!"<<endl;
return;
}
ListNode *tempPTR = Head;
cout<<"\n\t The List is: ";
while ( tempPTR != 0 ){
cout<< tempPTR->theData <<" ";
tempPTR = tempPTR->theNext;
}
cout<<endl<<endl;
}
//////////////////////////////////////
The test Driver:
//Driver test for integer Linked List.
#include <iostream.h>
#include "MyNODE.h"
// main Driver
int main(){
cout<< "\n\t This is the test for integer LinkedList."<<endl;
const int arraySize=11,
ARRAY[arraySize]={44,77,88,99,11,2,22,204,50,58,12};
cout << "\n\tThe array is: "; //print the numbers.
for (int i=0;i<arraySize; i++)
cout<<ARRAY[i]<<", ";
TheLinkedlist list; //declare the list
for(int index=0;index<arraySize;index++)
list.AppendAtBack( ARRAY[index] );//create the list
cout<<endl<<endl;
list.Print(); //print the list
return 0; //end of the program.
}