C Program on reversing linked list using stack

Create a linked list and then convert it into a stack. Again the stack is to be convert into a linked list so that the linked list is reversed.

#include< stdio.h>

#include< stdlib.h>

struct tag

{

int a;

struct tag *next;

};

int i=0;

struct tag *node,*p,*p1;

void create(struct tag *n)

{

char ch;

node=n;

printf("\n Want to create(y/n)");

ch=getche();

while(ch!='n')

{

node->next=(struct tag*)malloc(sizeof(struct tag));

node=node->next;

printf("\n Value");

scanf("%d",&node->a);

printf("\nany more(y/n)");

ch=getche();

}

node->next=NULL;

}

void display(struct tag*n)

{

node=n;

if(node==NULL)

i=0;

else

i=1;

while(node)

{

printf("%4d",node->a);

node=node->next;

}

}

struct tag *push(struct tag *p1,struct tag *p2)

{

p2->next=p1;

return(p2);

}

struct tag *delF(struct tag *n)

{

node=n->next;

n->next=node->next;

return(node);

}

struct tag *pop(struct tag *n)

{

node=n->next;

free(n);

return node;

}

void main()

{

struct tag *n,*link,*stack,*p;

clrscr();

link=NULL;

stack=NULL;

create(link);

printf("\nList is as follows\n");

display(link->next);

do

{

p=delF(link);

stack=push(stack,p);

}while(link->next!=NULL);

printf("\nList is as follows (after converting it into a stack.)");

display(link->next);

if(i==0)

printf("\nNo element in the list.");

printf("\nStack is\n");

display(stack);

n=link;

while(stack!=NULL)

{

n->next=stack;

n=n->next;

stack=pop(stack);

}

printf("\nStack is as follows (after converting it into a linked list.)");

display(stack);

if(i==0)

printf("\nNo element in the stack.");

printf("\nFinal list\n");

display(link->next);

getch();

}