//Doubly Linked List
#include <stdio.h>
#include <stdlib.h>
typedef struct node
{
int info;
struct node *prev, *next;
}NODE;
NODE* createlist(NODE *list);
NODE* insert(NODE *list, int num, int pos);
void display(NODE *list);
NODE* search(NODE *list, int n1);
NODE* delpos(NODE *list, int pos);
NODE* delvalue(NODE *list, int n2);
void main()
{
int num, n1, n2, n3, pos;
NODE *list=NULL, *temp;
list=createlist(list);
display(list);
printf("\nEnter Element to be search:\t");
scanf("%d", &n1);
temp=search(list, n1);
if(temp!=NULL)
printf(">>'%d' is found<<\n",n1);
else
printf(">>'%d' is not found<<\n",n1);
printf("\nEnter the node data to insert node:\t");
scanf("%d", &num);
printf("Enter the node position to insert node:\t");
scanf("%d", &pos);
list=insert(list,num,pos);
display(list);
printf("\nEnter node postion to delete that node:\t");
scanf("%d", &pos);
list=delpos(list, pos);
display (list);
printf("\nEnter node data to delete node:\t");
scanf("%d", &n2);
list=delvalue(list, n2);
display(list);
}
NODE* createlist(NODE *list)
{
int n, count;
NODE *temp, *newnode;
printf("How many nodes you want to enter? \n");
scanf("%d", &n);
for(count=1; count<=n; count++)
{
newnode=(NODE*)malloc(sizeof(NODE));
newnode->prev=newnode->next=NULL;
printf("Enter the node data:\t");
scanf("%d", &newnode->info);
if(list==NULL)
{
list=temp=newnode;
}
else
{
temp->next=newnode;
newnode->prev=temp;
temp=newnode;
}
}
return list;
}
NODE* insert(NODE *list, int num, int pos)
{
NODE *newnode, *temp;
int i;
newnode=(NODE*)malloc(sizeof(NODE));
newnode->prev=newnode->next=NULL;
newnode->info=num;
if(pos==1)
{
newnode->next=list;
list->prev=newnode;
list=newnode;
return list;
}
for(i=1,temp=list; i<pos-1 && temp!=NULL; i++)
temp=temp->next;
if(temp==NULL)
{
printf(">>position is out of range<< \n");
return list;
}
else
if(temp->next==NULL)
{
newnode->next=temp->next;
newnode->prev=temp;
temp->next=newnode;
return list;
}
else
{
newnode->next=temp->next;
temp->next->prev=newnode;
temp->next=newnode;
newnode->prev=temp;
return list;
}
}
void display(NODE *list)
{
NODE *temp=list;
for(temp=list; temp!=NULL; temp=temp->next)
{
printf("%d", temp->info);
printf("--->>");
}
printf("NULL \n");
}
NODE* search(NODE *list, int n1)
{
NODE *temp=list;
for(temp=list; temp!=NULL; temp=temp->next)
if(temp->info==n1)
return temp;
return NULL;
}
NODE* delpos(NODE *list, int pos)
{
NODE *temp=list, *temp1, *temp2;
int i;
if(pos==1)
{
list=list->next;
list->prev=NULL;
free (temp);
return list;
exit;
}
for(i=1,temp=list; i<pos-1 && temp!=NULL; i++)
temp=temp->next;
if(temp==NULL || temp->next==NULL)
{
printf(">>position out of range<< \n");
return list;
exit;
}
temp1=temp->next;
if(temp1->next==NULL)
{
temp->next=NULL;
free (temp1);
return list;
exit;
}
else
{
temp2=temp1->next;
temp2->prev=temp;
temp->next=temp2;
free (temp1);
return list;
exit;
}
}
NODE* delvalue(NODE *list, int n2)
{
NODE *temp=list, *temp1, *temp2;
if(list->info==n2)
{
list=list->next;
free (temp);
return list;
exit;
}
for(temp=list; temp->next!=NULL; temp=temp->next)
{
if(temp->next->info==n2)
{
temp1=temp->next;
if(temp1->next==NULL)
{
temp->next=NULL;
free (temp1);
return list;
exit;
}
else
{
temp2=temp1->next;
temp->next=temp2;
temp2->prev=temp;
free (temp1);
return list;
exit;
}
}
}
printf(">>Enter valid data<< \n");
return list;
}
