1. Linked list

2. Linked List
Linked lists are type of data structure, which is a way to represent data in memory. Memory is requested from the operating system as needed, with each additional piece of allocated memory added to our list.
For example, if we had the numbers 5, 6, 9, 2, our linked list might look like this: 6 5 9 2

3. Creating Linked List
In order for us to navigate our list, we must keep track of the address of each piece of allocated memory. We do this by creating a structure that contains a variable for storing our data as well as a pointer variable for storing the address of the next node in the list.
In the simplest case, a node in the linked list will have this form:
struct node {
int value;
struct node *next; };

4. Arrays vs Linked Lists
Linked lists are an alternative to using arrays to store multiple, related values. Why not just use arrays?
Arrays
Pros
Contiguous memory allows easy navigation and the use of row offsets
Easy on programmer
Cons
Can't easily insert/delete items - time complexity
Can't free after use if statically allocated arrays

5. Arrays vs Linked Lists Linked List Pros Cons
Don't need to know the number of elements in advance
Can insert new elements without moving other elements
Add/delete new elements
Can release unneeded memory
Cons
Not easy to understand and manage
Not easy to access a specific node

6. Linked List implementation in C
struct node {
int data;
struct node *next; }; A
200
300
400
200 2
300 4
400 6
NULL
Pointer
to head
node
data
next

7. Linked List implementation in C
struct node {
int data;
struct node *next; };
node *A;
A = NULL; //empty list A
200
300
400
200 2
300 4
400 6
NULL
Pointer
to head
node
data
next
int
node A
NULL

8. Linked List implementation in C
struct node {
int data;
struct node *next; };
node *A;
A = NULL; //empty list
node *temp = (node *) malloc(sizeof(node));
(*temp).data = 2;
(*temp).next = NULL;
A = temp;
200 2
300 4
400 6 A
NULL
data
next
Pointer
to head
node
int
200 2 A
NULL
temp

9. Linked List implementation in C
struct node {
int data;
struct node *next; };
node *A;
A = NULL; //empty list
node *temp = (node *) malloc(sizeof(node));
(*temp).data = 2;
(*temp).next = NULL;
A = temp;
200 2
300 4
400 6 A
NULL
data
next
Pointer
to head
node
int
200 2 A
NULL

10. Linked List implementation in C
struct node {
int data;
struct node *next; };
node *A;
A = NULL; //empty list
node *temp = (node *) malloc(sizeof(node));
temp -> data = 2;
temp -> next = NULL;
A = temp;
200 2
300 4
400 6 A
NULL
data
next
Pointer
to head
node
int
200 2 A
NULL

11. Linked List implementation in C
struct node {
int data;
struct node *next; };
node *A;
A = NULL; //empty list
node *temp = (node *) malloc(sizeof(node));
temp -> data = 2;
temp -> next = NULL;
A = temp;
temp = (node *) malloc(sizeof(node));
temp -> data = 4;
300
200 2 A
NULL 4
Traversal
node *temp1 = A;
while (temp1 -> next != NULL) {
temp1 = temp1 -> next;
printf (“temp1 -> data”); }
300
temp
NULL
temp1

12. Insert a node in the linked list
There are various ways to insert a node
At the beginning
At the end
At any specific position

13. Insert a node at the beginning

14. #include<stdio. h> #include<stdlib
#include<stdio.h> #include<stdlib.h> struct node { int data; struct node* next; }; struct node* head; void Insert(int x) { node *temp = (node*)malloc(sizeof(struct node)); temp->data = x; temp->next=head; head=temp; }
void Print(){
struct node*temp=head;
printf("List is:");
while(temp!=NULL) {
printf("%d ",temp->data);
temp=temp->next; }
printf("\n");
int main(){
head = NULL; //empty list
int n, i, x;
printf("How many numbers?\n");
scanf("%d",&n);
for (i=0;i<n;i++)
printf("Enter the number\n");
scanf("%d",&x);
Insert(x);
Print();

15. Insert a node at nth position

16. #include<stdio. h> #include<stdlib
#include<stdio.h> #include<stdlib.h> struct node { int data; struct node* next; }; struct node* head; void Insert(int data, int n) { node *temp1 = (node*)malloc(sizeof(struct node)); temp1->data = data; temp1->next=NULL; if(n==1){ temp1->next=head; head=temp1; return; } node* temp2=head; for(int i=0;i<n-2;i++) temp2=temp2->next; temp1->next=temp2->next; temp2->next=temp1;
void Print(){
struct node*temp=head;
printf("List is:");
while(temp!=NULL) {
printf("%d ",temp->data);
temp=temp->next; }
printf("\n");
int main(){
head = NULL; //empty list
Insert(2,1); //list:2
Insert(3,2);//list: 2,3
Insert(4,1);//list: 4,2,3
Insert(5,2); //list: 4,5,2,3
Print();

17. Delete a node at nth position

18. struct node*temp=head; printf("List is:"); while(temp!=NULL) {
void print(){
struct node*temp=head;
printf("List is:");
while(temp!=NULL) {
printf("%d ",temp->data);
temp=temp->next; }
printf("\n");
void delete1(int n) {
struct node* temp1 = head;
if (n==1){
head = temp1->next; //head now points to the second node
free(temp1);
return; }
int i;
for(i=0;i<n-2;i++)
temp1=temp1->next; //temp1 points to (n-1)th node
struct node* temp2 = temp1->next; //nth node
temp1->next = temp2->next; //(n+1)th node
free(temp2); //delete temp2
int main(){
head = NULL; //empty list
Insert(2, 1);
Insert(4, 2);
Insert(6, 1);
Insert(5, 2); //list: 2,4,6,5
print();
int n;
printf("Enter a position\n");
scanf("%d",&n);
delete1(n);
#include<stdio.h> #include<stdlib.h> struct node { int data; struct node* next; }; struct node* head; void Insert(int data, int n) { node *temp1 = (node*)malloc(sizeof(struct node)); temp1->data = data; temp1->next=NULL; if(n==1){ temp1->next=head; head=temp1; return; } node* temp2=head; for(int i=0;i<n-2;i++) temp2=temp2->next; temp1->next=temp2->next; temp2->next=temp1;

19. Tutorial on Doubly Linked List
Can you create a doubly linked-list? Insert a node in or delete a node from the list? Search a node?
structures-doubly-linked-list-with-c-program-source-code

20. Study Reference Stack and Queue
structures-stacks--with-c-program-source-code
structures-queues--with-c-program-source-code