Double Linked List query - c

Question

so i have created a program which uses double linked list and
performs some operations on it . The problem is that it displays garbage
values
at the end every time i try to create a linked list and then display it.
whats wrong in my code?(sorry! for the bad indentations)
if the linked list i created has elements say 15 and 16, it displays it as
15 16 25710 0 0
#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
struct dll
{
int data;
struct dll *llink;
struct dll *rlink;
};
typedef struct dll *node;
node head=NULL;
void create();
int search(int u);
void insert(int num1);
void Delete(int num2);
void display();
node getnode();
int main()
{
int i,num,o;
while(1)
{
printf("\n1.create a list\n 2. insert before a search node\n 3. delete a node\n 4.display\n 5.exit\n");
scanf("%d",&num);
switch(num)
{
case 1 :
create();
break;
case 2 :
printf("enter the value before which you want to enter the node\n");
scanf("%d",&i);
insert(i);
break;
case 3 :
printf("enter the value to be deleted\n");
scanf("%d",&o);
Delete(o);
break;
case 4 :
printf("the linked list has :\n");
display();
break;
case 5 :
getch();
exit(1);
default :
printf("enter the correct option\n");
break;
}
}
}
node getnode()
{
node temp1;
temp1=(node)malloc(sizeof(node));
temp1->llink=NULL;
temp1->rlink=NULL;
return temp1;
}
void create()
{
node nn;
int num,y;
if(head==NULL)
head=getnode();
while(1)
{
printf("enter the data for the node");
scanf("%d",&num);
head->data=num;
printf("do you want to create another node(1/0):\n");
scanf("%d",&y);
if(y==1)
{
nn=getnode();
nn->rlink=head;
head->llink=nn;
head=nn;
nn=NULL;
}
else
break;
}
}
void insert (int num1)
{
int i,n,k;
node temp=head,nn;
n=search(num1);
if(n==0)
{
printf("element not present in the linked list");
}
if(n==1)
{
nn=getnode();
printf("enter the data for the node");
scanf("%d",&k);
nn->data=k;
nn->rlink=head;
head->llink=nn;
head=nn;
nn=NULL;
}
else
{
for(i=2; i<=n; i++)
temp=temp->rlink;
nn=getnode();
temp->llink->rlink=nn;
nn->llink=temp->llink;
nn->rlink=temp;
temp->llink=nn;
}
}
void Delete(int num2)
{
node temp=head;
int p,i;
p=search(num2);
if(p==0)
{
printf("no element is found");
}
if(p==1)
{
printf("the deleted element is %d",head->data);
head=head->rlink;
head->llink=NULL;
free(temp);
}
else
{
for(i=2; i<=p; i++)
{
temp=temp->rlink;
}
temp->llink->rlink=temp->rlink;
temp->rlink->llink=temp->llink;
free(temp);
temp=temp->rlink;
}
}
int search(int u)
{
node temp=head;
int pos=0;
if(u==head->data)
return 1;
else
{
while(temp!=NULL)
{
pos++;
if(temp->data==u)
{
printf("element found\n");
return(pos);
}
temp=temp->rlink;
}
}
if(temp==NULL)
{
return 0;
}
return -1;
}
void display()
{
node temp=head;
while(temp!=NULL)
{
printf("%d\n",temp->data);
temp=temp->rlink;
}
}

Answer 1

This:
temp1=(node)malloc(sizeof(node));
is a major error. Since you're "hiding a star", and node is a typedef for a pointer type, you're not allocating enough memory. It should be:
node temp1 = malloc(sizeof *temp1);
But I really recommend against typedefing a pointer away, it just makes things confusing.