Basic C++ Constructs

C++ selections

one way selection if
two way selection if ... else
multiway selection --- switch statement
conditional expression -- predicate ? :

C++ Reptitions

while
do .... while
for

C++ Functions

function prototype declaration
function definition
function calling statement

Generic C++ Linked Lists

General Components

C++ structured data type

C++ pointer variable structure member

linked list manipulator functions

Manipulator Functions

Inserts

Deletes

Referencing

Modifying

Linked Lists vs Arrays

memory allocation

element referencing

complexity of manipulating functions

abstract viewpoint

Some Generic Linked List Functions

Using this

**Generic C++ struct Data Type**

struct std_struct
{
int firstmember;
float secondmember;
std_struct *next;
};

Generic C++ Linked List Insert at Front Function

std_struct * insert_at_front (std_struct current, std_struct newitem)

/* insert_at_front inserts the record pointed to by its second parameter newitem in the beginning of the
linked list pointed to by its first parameter, parameter, current. Note that the values of the fields for
the record pointed to by newitem have been initialized before the call to insert_at_front. */

{
std_struct *temp;

temp = current;
if (empty (temp)) current = newitem;

else
{
newitem->next = temp;
current = newitem;
};
return current;
}

Generic C++ Linked List Insert at End Function

std_struct * insert_at_end (std_struct head, std_struct newitem)

/* insert_at_end inserts the record pointed to by its second parameter, newitem, at the end of the linked list
pointed to by its first parameter, head. Note that the values of the fields for the record pointed to by newitem
have been initialized before the call to insert_at_end. The function returns the pointer to the linked list of
elements with the new element inserted. */

{
std_struct *current;

current = head;
if (empty (current)) head = newitem;

else
{
while (current->next != NULL)
current = current->next;

current->next = newitem;
}
return head;
}

Generic C++ Linked List Insert In Order Function

std_struct * insert_in_order (std_struct *head, std_struct *newitem)

/* insert_in_order inserts the record pointed to by its second parameter, newitem, into the list
pointed to by its first parameter, head. It maintains the list's lowest to highest order of the firstmember.
insert_in_order returns the pointer to the first element of the linked list with the new element inserted in order. */

{
std_struct * current, dummy;

current = head;
if (empty (current)) current = insert_at_front (head, newitem);

else if (newitem->firstmember <= current->firstmember)
current = insert_at_front (head, newitem);

else
{
dummy = *newitem;
current = insert_at_end (head, &dummy);
while ( newitem->firstmember > current->next->firstmember)
current = current->next;

newitem->next = current->next;
current->next = newitem;
current = head;
current = delete_last (head);
}
return current;
}

Generic C++ Linked List Delete First Function

std_struct * delete_first (std_struct *current)

/* delete_first deletes the first element of the list pointed to by its parameter, current.
delete_first returns the pointer to the linked list of elements with the first element removed */

{
std_struct *temp;

temp = current;
if (empty (temp)) temp = NULL;
else if (temp->next == NULL)
{
delete temp;
temp = NULL;
}
else
{
current = temp->next;

delete temp;
temp = current;
}
return temp;
}

Generic C++ Linked List Empty Function

int empty (std_struct *temp)

/* empty tests its pointer variable parameter, temp,
for NULL and returns the integer value of the result of the test */

{
return (temp == NULL);
}

Generic C++ Linked List Delete Last Function

std_struct * delete_last (std_struct *head)

/* delete_last deletes the last element of the list pointed to by its parameter, head.
delete_last returns the pointer to the linked list of elements with the last element removed */

{
std_struct *current;

current = head;
if (empty (current)) current = NULL;
else if (current->next == NULL)
{
delete current;
current = NULL;
}
else
{
while (current->next->next != NULL)
current = current->next;

delete current->next;
current->next = NULL;
current = head;
}
return current;
}