C program error

Question

The following code is a program for insertion and deletion in a doubly linked list at various positions. It is getting compiled, but not running as it shows 3 linker errors. Please help ASAP. Thankyou. Regards.

 

 

#inlude<alloc.h>

#include<conio.h>

#include<stdio.h>

#include<stdlib.h>

struct node

{

struct node *prev;

int n;

struct node* next;

}*h,*temp,*temp1,*temp2,*temp4;

void create();

void insert_beg();

void insert_end();

void delete_pos();

void traverse();

int count = 0;

void main()

{

int ch;

clrscr();

printf("\n1.Create list\n2.Insert at beginning\n3.Insert at end\n4.Delete from given position\n5.Display");

while(1)

{

printf("\n Enter your choice: ");

scanf("%d", &ch);

switch(ch)

{

case 1:

create_list();

break;

case 2:

insert_beg();

break;

case 3:

insert_end();

break;

case 4:

delete_pos();

break;

case 5:

traverse();

break;

default:

printf("\n Wong choice entered");

}

getch();

}

}

void create()

{

int data;

temp=(struct node *)malloc(1*sizeof(struct node));

temp->prev=NULL;

temp->next=NULL;

printf("\n Enter the data: ");

scanf("%d",&data);

temp->n=data;

count++;

}

void insert_beg()

{

if(h==NULL)

{

create();

h=temp;

temp1=h;

}

else

{

create();

temp->next=h;

h->prev=temp;

h=temp;

}

}

void insert_end()

{

if(h==NULL)

{

create();

temp->next=temp;

temp->prev=temp1;

temp1=temp;

}

}

void del_pos()

{

int i=1,pos;

printf("\n Enterposition to be deleted: ");

scanf("%d", &pos);

temp2=h;

if((pos<1) || (pos>=count + 1))

{

printf("\n Error: Position out of range to delete");

return;

}

if(h==NULL)

{

printf("\n Error: Empty iist");

return;

}

else

{

while(i < pos)

{

temp2=temp2->next;

i++;

}

if(i==1)

{

if(temp2->next==NULL)

{

printf("Node deleted from list");

free(temp2);

temp2=h=NULL;

return;

}

}

if(temp->next == NULL)

{

temp2->prev->next=NULL;

free(temp2);

printf("Node deleted from list");

return;

}

temp2->next->prev = temp2->prev;

if(i!=1)

temp2->prev->next=temp2->next;

if(i==1)

h=temp2->next;

printf("\n Node deleted");

free(temp);

}

count--;

}

void diaplay()

{

temp2=h;

if(temp2==NULL)

{

printf("List empty to traverse\n");

return;

}

printf("\n Lined list is:\n ");

while(temp2->next!=NULL)

{

printf("%d", temp2->n);

temp2=temp2->next;

}

printf("%d", temp2->n);

getch();

}