# C program of Doubly Link list

Doubly link list is a list in which there is three field first for storing the address of the previous node second for data field and third for the address of the next node.

Here in this article we will create a doubly Link list and create a function for Insertion Node at first Position and also create a Function for delete Nodes from starting.

__Code:-__#include<stdio.h>

#include<stdlib.h>

// function for define the structure of node

struct node

{

int data;

struct node *pre,*next;

};

struct node *head=NULL;

// function for creating the node

struct node *creatnode()

{

struct node* t;

t=(struct node*)malloc(sizeof(struct node));

return(t);

}

// function for insert the node

// at starting for the list

void Insert()

{

struct node *t;

t=creatnode();

printf(“Enter a number “);

scanf(“%d”,&t->data);

t->pre=NULL;

t->next=NULL;

if(head==NULL)

{

head=t;

}

else

{

t->next=head;

head->pre=t;

head=t;

}

}

// function for delete the node

// from the starting

void delete()

{

struct node *t;

if(head==NULL)

printf(“List is Emptyn”);

else

{

t=head;

head=head->next;

head->pre=NULL;

free(t);

}

}

// function for view the list

void viewlist()

{

struct node *t;

if(head==NULL)

printf(“List is Emptyn”);

else

{

t=head;

while(t->next!=NULL)

{

printf(“%d “,t->data);

t=t->next;

}

}

}

// driver function

int main()

{

int ch;

head=creatnode();

while(1)

{

printf(“n Pressn”);

printf(“1. Insertionn”);

printf(“2. deleten”);

printf(“3. View Listn”);

printf(“4. Exitn”);

printf(“Enter Your Choicen”);

scanf(“%d”,&ch);

switch(ch)

{

case 1:

Insert();

break;

case 2:

delete();

break;

case 3:

viewlist();

break;

case 4:

exit(0);

default :

printf(“Invailid key”);

}

}

return 0;

}

__Output:-__Press

1. Insertion

2. delete

3. View List

4. Exit

Enter Your Choice 1

Enter a number 12

Press

1. Insertion

2. delete

3. View List

4. Exit

Enter Your Choice 1

Enter a number 34

Press

1. Insertion

2. delete

3. View List

4. Exit

Enter Your Choice

3

34 12

Press

1. Insertion

2. delete

3. View List

4. Exit

Enter Your Choice

2

Press

1. Insertion

2. delete

3. View List

4. Exit

Enter Your Choice 4

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