Program
: Doubly Linked List – Insertion
// Insertion in doubly linked list
(Insert First, Last and node at desire position)
#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
struct link
{
int
no;
struct
link *next;
struct
link *pre;
};
struct link *node,*start,*new1;
void create_link(struct link
*node);
void display(struct link *node);
void insert_first(struct link
*node);
void insert_last(struct link *node);
void insert_desireposition(struct
link *node);
void main()
{
int
ch;
clrscr();
do
{
printf("\n
Doubly Linked List");
printf("\n---------------------------");
printf("\n
1. Create Linked list");
printf("\n
2. Traverse Linked list");
printf("\n
3. Insert First node");
printf("\n
4. Insert Last node");
printf("\n
5. Insert node at Desire Position");
printf("\n
6. Exit");
printf("\n-----------------------------");
printf("\n
Enter your choice:-");
scanf("%d",&ch);
switch(ch)
{
case
1:
node=(struct
link *)malloc(sizeof(struct link));
create_link(node);
printf("\n
List is as follow");
display(node);
break;
case
2:
printf("\n
Output\n");
display(node);
break;
case
3:
insert_first(node);
printf("\n
After Inserting First Node");
display(node);
break;
case
4:
insert_last(node);
printf("\n
After Inserting Last Node");
display(node);
break;
case
5:
insert_desireposition(node);
printf("\n
After Inserting At Desire Position");
display(node);
break;
case
6:
exit(0);
break;
default:
printf("\n
Wrong Choice");
}
}while(ch!=6);
getch();
}
void create_link(struct link
*node)
{
char
ans;
start->next=NULL;
start->pre=NULL;
node=start;
fflush(stdin);
printf("\n
Enter 'n' for break:-");
ans=getchar();
while(ans!='n')
{
node->next=(struct
link *)malloc(sizeof(struct link));
node->next->pre=node;
node=node->next;
printf("\n
Enter data for node:-");
scanf("%d",&node->no);
node->next=NULL;
fflush(stdin);
printf("\n
Enter 'n' for break:-");
ans=getchar();
}
}
void display(struct link *node)
{
node=start->next;
while(node)
{
printf("\n %d",node->no);
node=node->next;
}
}
void insert_first(struct link
*node)
{
node=start->next;
new1=(struct
link *)malloc(sizeof(struct link));
printf("\n
Insert data for first node:-");
scanf("%d",&new1->no);
node->pre->next=new1;
new1->pre=node->next;
new1->next=node;
node->pre=new1;
}
void insert_last(struct link *node)
{
node=start->next;
while(node->next)
{
node=node->next;
}
new1=(struct
link *)malloc(sizeof(struct link));
printf("\n
Insert data for last node:-");
scanf("%d",&new1->no);
node->next=new1;
new1->pre=node;
new1->next=NULL;
}
void insert_desireposition(struct
link *node)
{
int
node_no=1,insert_no,flag=0;
node=start->next;
printf("\n
Enter position where you want to insert new node :-");
scanf("%d",&insert_no);
while(node)
{
if(node_no==insert_no)
{
new1=(struct
link *)malloc(sizeof(struct link));
printf("\n
Insert data for new node:- ");
scanf("%d",&new1->no);
node->pre->next=new1;
new1->pre=node->pre;
new1->next=node;
node->pre=new1;
flag=1;
break;
}
else
{
node=node->next;
}
node_no++;
}
if(flag==0)
{
printf("\n
Position not found");
}
}
Posted By : Ruchita Pandya
