Checking few methods of node deletion in link list in C++

Question

These methods are related to node deletion of  doubly  linked list . please check them and if there is error , solve them.

 

 

class LinkListNode

{

friend class LinkList;

private:

int data;

LinkListNode *llink, * rlink;

};

class LinkList

{

private:

LinkListNode *start;

};

// Basic form of deleting node from LinkList

void delete ( int x , node * start )

{

node *p ;

p = start → rlink ;

while ( p && p →data < x )

{

p = p → rlink ;

if ( p = = Null | | p → data > x )

return " There isn't any data " ;

( p →llink ) → rlink = p → rlink ;

( p →rlink ) → llink = p → llink ;

delete ( p ) ;

}

}

First Fuction:

// deleting node which are at the middle of the Doubly LinkList (Second Type: first node and last node have link between together.)

void LinkList::Delete(ListLink *x)

{

if(x==start)

cout<<" There is no data to delete ."

else

{

x → llink → rlink = x → rlink;

x → rlink → llink = x → llink;

delete x;

}

}

Second Function:

// deleting node which are at the end of the Doubly LinkList(Second type)

void LinkList::Delete(ListLink *x)

{

if(x==start)

cout<<"There is no data to delete."

else

{

x → llink = x → rlink;

x → rlink → llink = x → llink;

delete x;

}

}

Third Function:

// deleting node which are at the beginning of the Doubly LinkList(Second Type)

void LinkList::Delete(ListLink *x)

{

if(x==start)

cout<<"There is no data to delete."

else

{

x → rlink → llink = x → llink;

x → llink = x → rlink;

delete x;

}

}

Forth Function:

// deleting node which are at the Beginning of the Doubly LinkList(First Type: First node and last node doesn’t have any link between them.)

void LinkList::Delete(ListLink *x)

{

if(x==start)

cout<<"There is no data to delete."

else

{

x → llink → rlink = null;

x → llink = null;

delete x;

}

Fifth Function:

// deleting node which are at the end of the Doubly LinkList (First type)

void LinkList::Delete(ListLink *x)

{

if(x==start)

cout<<"There is no data to delete."

else

{

x → rlink = null;

x → rlink → llink = null;

delete x;

}

Sixth Function:

Note: The Sixth Function and First Function are the same.

void LinkList::Delete(ListLink *x)

{

if(x==start)

cout<<" There is no data to delete ."

else

{

x → llink → rlink = x → rlink;

x → rlink → llink = x → llink;

delete x;

}