linked list with its operations

7/28/2019 Linked List With Its Operations

1/15


2/15

Difference between Linked lists and arrays:

An array is a static data structure. This means the

length of array cannot be altered at run time.

While, a linked list is a dynamic data structure. In an array, all the elements are kept at

consecutive memory locations while in a linked

list the elements (or nodes) may be kept at anylocation but still connected to each other.


3/15

Insertion

Insert as a first node

Insert as a last node

Insert after a node

Insert before a node

Deletion

Delete first node

Delete last node

Traversal


4/15

For insertion:

A record is created holding the new item.

The nextpointer of the new record is set to link it tothe item which is to follow it in the list.

The nextpointer of the item which is to precede itmust be modified to point to the new item.

For deletion:

The nextpointer of the item immediately precedingthe one to be deleted is altered, and made to point tothe item following the deleted item.


5/15

head 48 17 14293

Note:

There is no work to find the correct location

Empty or not, head will point to the right location


6/15

void insertf()

{

struct studinfo *newnode;

newnode=(struct studinfo *) malloc(sizeof(struct studinfo)); /*Creating new node*/

printf("\nEnter a new record : marks and name ");

scanf("%d%s",&newnode->marks,newnode->name);newnode->next=NULL;

if(start==NULL)

start = newnode;

else

{

newnode->next = start;

start = newnode;

}

}


7/15

Note: Find the end of the list

Recursion or iteration

48 17 142head //93 //


8/15

void insertl()

{

struct studinfo *newnode, *ptr;

newnode=(struct studinfo *) malloc(sizeof(struct studinfo));


scanf("%d%s",&newnode->marks,newnode->name);newnode->next=NULL;

if (start == NULL)

start =newnode;

else

{

ptr =start;

while (ptr->next != NULL)

ptr= ptr->next;

ptr->next = newnode;

}

}


9/15

Head17 48 142 //93 //142

Note:

Used when order is important

Go to the node that should follow the one to add, Recursion or

iteration


10/15

void inserta()

{

int cnt=1, no;

struct studinfo *ptr,*prevptr, *newnode;

printf("\nEnter number ...");

scanf("%d",&no);

ptr=start;while (cnt != no)

{ ptr = ptr->next;

cnt++; }

newnode=(struct studinfo *) malloc(sizeof(struct studinfo));


scanf("%d%s",&newnode->marks,newnode->name);newnode->next =NULL;

newnode->next = ptr->next;

ptr->next = newnode;

}


11/15

void insertb()

{

int cnt=1, no;

struct studinfo *ptr,*prevptr, *newnode;

printf("\nEnter number ...");

scanf("%d",&no);

ptr=start;if(no==1)

{

insertf();

}

else

{while(cnt !=no)

{

prevptr=ptr;

ptr = ptr->next;

cnt++;

}


12/15

newnode=(struct studinfo *) malloc(sizeof(struct

studinfo));


scanf("%d%s",&newnode->marks,newnode->name);

newnode->next=ptr;

prevptr->next=newnode;

}

}


13/15

void deletef(){

struct studinfo *ptr;if (start == NULL)

{printf("\n List is empty");return;}

ptr=start;

start=start->next;free(ptr);

}


14/15

void deletel(){

struct studinfo *ptr,*prevptr;

ptr=start;

if (ptr->next==NULL)

start = NULL;

else

{while(ptr->next!=NULL)

{

prevptr=ptr;

ptr=ptr->next;

}

prevptr->next =NULL;

}free(ptr);

}


15/15

void traverse(){

struct studinfo *ptr;

if (start == NULL)

{

printf("\n List is empty");

return;}

ptr= start;

while (ptr !=NULL)

{

printf("\nRecord: marks and name %d %s\n",ptr->marks, ptr->name);

ptr = ptr->next;

}

getch();

}

linked list with its operations

Documents