A Singly Linked List

What is a singly linked list? A linked list is a series of nodes in memory such that:

1. There is a starting node.

2. Each node contains a pointer that points to the next or child node.

3. If a node does not have a child node then its pointer is set to NULL.

4. Each node contains data, maybe a lot of it.

5. The linked list also has functions that manage the list by performing additions,

deletions, changing the data of a node, returning the number of nodes, etc., etc.

What is a linked list used for? A linked list is used for the same purposes as an array. However, the linked list has some

advantages:

An array is of fixed size (unless it is dynamically allocated), a linked list can grow by

grabbing new memory off the heap as needed.

If you store a list in an array and then delete an item in the middle, then you must move a lot

of items down one to close up the gap. But in a linked list, you simply reroute the pointers

around the node to delete, and then you delete it.

A singly linked list class The class definition for a node #include

#include

using namespace std;

typedef string listType;

class node

{

public:

node (listType);

voidsetData (listType);

voidsetNext (node*);

listTypegetData () const;

node* getNext () const;

private:

listType data;

node* next;

};

The functions for the node class #include "node.h"

node::node (listType it)

{

//pre-condition: it is the datum to be stored in the node

//post-condition: it gets stored in the node

data = it;

next = NULL;

}

void node::setData (listType it)

{

data = it;

}

void node::setNext (node* aNode)

{

next = aNode;

}

listType node::getData () const

{

return data;

}

node* node::getNext () const

{

return next;

}

The class definition for the linked list #include "node.h"

class linked

{

public:

linked ();

linked (linked&);

linked (listType [], int);

~linked ();

intgetSize ();

voidaddOnEnd (listType);

voidinsertBefore (int, listType);

voiddeleteLink (int);

voidsetDataInLink (int, listType);

listTypegetNthData (int);

private:

node* head;

node* tail;

int size;

voiddeleteAll ();

node* getNthAddress (int);

voiddeleteWithOneNode ();

voiddeleteAtBeginning ();

voiddeleteLast ();

voiddeleteInMiddle (int);

};