Program to reverse the elements of a single linked list

Program to reverse the elements of a single linked list in C

#include<stdio.h>
struct node
{
int data;
struct node *next;
} *head,*temp,*temp1,*first,*last;
void create();
void swap(struct node*,struct node*);
void reverse();
void print();

void main()
{
create();
printf("\nElements in the entered list:\n");
print();
reverse();
printf("\nElements after reversing the entered list:\n");
print();
}

void create()
{
int num;
printf("\nEnter element or enter -1 to exit\n");
head=(struct node*)malloc(sizeof(struct node));
scanf("%d",&num);
if(num==-1)
{
head=NULL;
}
else
{
head->data=num;
head->next=NULL;
}
while(head!=NULL)
{
printf("\nEnter element or enter -1 to exit\n");
scanf("%d",&num);
if(num==-1)
{break;}
else
{
temp=head;
while(temp->next!=NULL)
{
temp=temp->next;
}
temp1=(struct node*)malloc(sizeof(struct node));
temp1->data=num;
temp1->next=NULL;
temp->next=temp1;
}
}
}
/* Reverse function is for reversing the linked list.It swaps the first and last element,first+1 and last-1 and so on.until it reaches the middle of linked list. */
void reverse()
{
first=head;
last=head;
while(last->next!=NULL)
{
last=last->next;
}
while(first!=last&&last->next!=first)
{
swap(first,last);
for(temp=first;temp->next!=last;temp=temp->next);
last=temp;
first=first->next;
}
}
void print()
{
struct node *head1=head;
while(head1!=NULL)
{
printf("%d\t",head1->data);
head1=head1->next;
}
}
/*Swap functions takes first and last node's pointers and swaps the elements in that nodes*/
void swap(struct node *p,struct node *q)
{
int k;
k=p->data;
p->data=q->data;
q->data=k;
}