#include <stdio.h>
#include <stdlib.h>
/*
* Basic structure of Node
*/
struct node
{
int data;
struct node *prev;
struct node *next;
} *head, *last;
/*
* Functions used in this program
*/
void createList(int n);
void displayList();
void deleteFromBeginning();
void deleteFromEnd();
void deleteFromN(int position);
int main()
{
int n, data, choice = 1;
head = NULL;
last = NULL;
/*
* Run forever until user chooses 0
*/
while (choice != 0)
{
printf("============================================\n");
printf("DOUBLY LINKED LIST PROGRAM\n");
printf("============================================\n");
printf("1. Create List\n");
printf("2. Delete node - from beginning\n");
printf("3. Delete node - from end\n");
printf("4. Delete node - from N\n");
printf("5. Display list\n");
printf("0. Exit\n");
printf("--------------------------------------------\n");
printf("Enter your choice : ");
scanf("%d", &choice);
switch (choice)
{
case 1:
printf("Enter the total size of nodes in list: ");
scanf("%d", &n);
createList(n);
break;
case 2:
deleteFromBeginning();
break;
case 3:
deleteFromEnd();
break;
case 4:
printf("Enter the node position which you want to delete: ");
scanf("%d", &n);
deleteFromN(n);
break;
case 5:
displayList();
break;
case 0:
break;
default:
printf("Error! Invalid choice. Please choose between 0-5");
}
printf("\n\n\n\n\n");
}
return 0;
}
/**
* Creates a doubly linked list of n nodes.
* @n Number of nodes to be created
*/
void createList(int n)
{
int i, data;
struct node *newNode;
if (n >= 1)
{
/*
* Creates and links the head node
*/
head = (struct node *)malloc(sizeof(struct node));
printf("Enter data of 1 node: ");
scanf("%d", &data);
head->data = data;
head->prev = NULL;
head->next = NULL;
last = head;
/*
* Create and link rest of the n-1 nodes
*/
for (i = 2; i <= n; i++)
{
newNode = (struct node *)malloc(sizeof(struct node));
scanf("%d", &data);
newNode->data = data;
newNode->prev = last; // Link new node with the previous node
newNode->next = NULL;
last->next = newNode; // Link previous node with the new node
last = newNode; // Make new node as last node
}
printf("\nDOUBLY LINKED LIST CREATED !! \n");
}
}
/**
* Display the content of the list from beginning to end
*/
void displayList()
{
struct node *temp;
int n = 1;
if (head == NULL)
{
printf("List is empty.\n");
}
else
{
temp = head;
printf("DATA IN THE LIST:\n");
while (temp != NULL)
{
printf(" %d ", n, temp->data);
n++;
/* Move the current pointer to next node */
temp = temp->next;
}
}
}
/**
* Delete or remove the first node of the doubly linked list
*/
void deleteFromBeginning()
{
struct node *toDelete;
if (head == NULL)
{
printf("Unable to delete. List is empty.\n");
}
else
{
toDelete = head;
head = head->next; // Move head pointer to 2 node
if (head != NULL)
head->prev = NULL; // Remove the link to previous node
free(toDelete); // Delete the first node from memory
printf("SUCCESSFULLY DELETED NODE FROM BEGINNING OF THE LIST.\n");
}
}
/**
* Delete or remove the last node of the doubly linked list
*/
void deleteFromEnd()
{
struct node *toDelete;
if (last == NULL)
{
printf("Unable to delete. List is empty.\n");
}
else
{
toDelete = last;
last = last->prev; // Move last pointer to 2nd last node
if (last != NULL)
last->next = NULL; // Remove link to of 2nd last node with last node
free(toDelete); // Delete the last node
printf("SUCCESSFULLY DELETED NODE FROM END OF THE LIST.\n");
}
}
/**
* Delete node from any position in the doubly linked list
*/
void deleteFromN(int position)
{
struct node *current;
int i;
current = head;
for (i = 1; i < position && current != NULL; i++)
{
current = current->next;
}
if (position == 1)
{
deleteFromBeginning();
}
else if (current == last)
{
deleteFromEnd();
}
else if (current != NULL)
{
current->prev->next = current->next;
current->next->prev = current->prev;
free(current); // Delete the n node
printf("SUCCESSFULLY DELETED NODE FROM %d POSITION.\n", position);
}
else
{
printf("Invalid position!\n");
}
}
Output
============================================
DOUBLY LINKED LIST PROGRAM
============================================
1. Create List
2. Delete node - from beginning
3. Delete node - from end
4. Delete node - from N
5. Display list
0. Exit
--------------------------------------------
Enter your choice : 1
Enter the total number of nodes in list: 5
Enter data of 1 node: 10
Enter data of 2 node: 20
Enter data of 3 node: 30
Enter data of 4 node: 40
Enter data of 5 node: 50
DOUBLY LINKED LIST CREATED SUCCESSFULLY
============================================
DOUBLY LINKED LIST PROGRAM
============================================
1. Create List
2. Delete node - from beginning
3. Delete node - from end
4. Delete node - from N
5. Display list
0. Exit
--------------------------------------------
Enter your choice : 5
DATA IN THE LIST:
DATA of 1 node = 10
DATA of 2 node = 20
DATA of 3 node = 30
DATA of 4 node = 40
DATA of 5 node = 50
============================================
DOUBLY LINKED LIST PROGRAM
============================================
1. Create List
2. Delete node - from beginning
3. Delete node - from end
4. Delete node - from N
5. Display list
0. Exit
--------------------------------------------
Enter your choice : 2
SUCCESSFULLY DELETED NODE FROM BEGINNING OF THE LIST.
============================================
DOUBLY LINKED LIST PROGRAM
============================================
1. Create List
2. Delete node - from beginning
3. Delete node - from end
4. Delete node - from N
5. Display list
0. Exit
--------------------------------------------
Enter your choice : 5
DATA IN THE LIST:
DATA of 1 node = 20
DATA of 2 node = 30
DATA of 3 node = 40
DATA of 4 node = 50
============================================
DOUBLY LINKED LIST PROGRAM
============================================
1. Create List
2. Delete node - from beginning
3. Delete node - from end
4. Delete node - from N
5. Display list
0. Exit
--------------------------------------------
Enter your choice :
3
SUCCESSFULLY DELETED NODE FROM END OF THE LIST.
============================================
DOUBLY LINKED LIST PROGRAM
============================================
1. Create List
2. Delete node - from beginning
3. Delete node - from end
4. Delete node - from N
5. Display list
0. Exit
--------------------------------------------
Enter your choice : 5
DATA IN THE LIST:
DATA of 1 node = 20
DATA of 2 node = 30
DATA of 3 node = 40
============================================
DOUBLY LINKED LIST PROGRAM
============================================
1. Create List
2. Delete node - from beginning
3. Delete node - from end
4. Delete node - from N
5. Display list
0. Exit
--------------------------------------------
Enter your choice : 4
Enter the node position which you want to delete: 2
SUCCESSFULLY DELETED NODE FROM 2 POSITION.
============================================
DOUBLY LINKED LIST PROGRAM
============================================
1. Create List
2. Delete node - from beginning
3. Delete node - from end
4. Delete node - from N
5. Display list
0. Exit
--------------------------------------------
Enter your choice : 5
DATA IN THE LIST:
DATA of 1 node = 20
DATA of 2 node = 40
============================================
DOUBLY LINKED LIST PROGRAM
============================================
1. Create List
2. Delete node - from beginning
3. Delete node - from end
4. Delete node - from N
5. Display list
0. Exit
--------------------------------------------
Enter your choice : 0
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