#include <stdio.h>
#include <stdlib.h>
typedef struct node
{
	int data;
	struct node* next;
}node;
void push(node **head_ref, int new_data);
bool isPresent(node *head, int data);
node *getUnion(node *head1,node *head2)
{
	node *result = NULL;
	node *t1 = head1, *t2 = head2;
	while(t1 != NULL)
	{
		push(&result, t1->data);
		t1 = t1->next;
	}
	while(t2 != NULL)
	{
		if(!isPresent(result, t2->data))
			push(&result, t2->data);
		t2 = t2->next;
	}
	return result;
}
node *getIntersection(node *head1,node *head2)
{
	node *result = NULL;
	node *t1 = head1;
	while( t1 != NULL )
	{
		if(isPresent(head2, t1->data))
			push(&result, t1->data);
		t1 = t1->next;
	}
	return result;
}
void push(node**head_ref, int new_data)
{
	node* new_node = (node*)malloc(sizeof(node));
	new_node->data = new_data;
	new_node->next = (*head_ref);
	(*head_ref) = new_node;
}

void printList(struct node *node)
{
	while( node != NULL )
	{
		printf("%d ", node->data);
		node = node->next;
	}
}

bool isPresent(node *head, int data)
{
	node *t = head;
	while(t != NULL)
	{
		if( t->data == data ) return 1;
		t = t->next;
	}
	return 0;
}

int main()
{
	node* head1 = NULL;
	node* head2 = NULL;
	node* intersecn = NULL;
	node* unin = NULL;

	push (&head1, 20);
	push (&head1, 4);
	push (&head1, 15);
	push (&head1, 10);

	push (&head2, 10);
	push (&head2, 2);
	push (&head2, 4);
	push (&head2, 8);

	intersecn = getIntersection (head1, head2);
	unin = getUnion (head1, head2);

	printf ("\n First list is \n");
	printList (head1);

	printf ("\n Second list is \n");
	printList (head2);

	printf ("\n Intersection list is \n");
	printList (intersecn);

	printf ("\n Union list is \n");
	printList (unin);

	printf("\n");
	return 0;
}