Create two singly linked lists and perform the intersection operations

A ‘C’ program to create two singly linked lists and perform the intersection operations on two lists and display the resultant list.

Singly linked lists operations

#include

#include

/* Link list node */
struct node {
  int data;
  struct node * next;
};

/* A utility function to insert a node at the begining of a linked list*/
void push(struct node ** head_ref, int new_data);

/* A utilty function to chec if given data is present in a list */
int isPresent(struct node * head, int data);

/* Function to get union of two linked lists head1 and head2 */
/* Function to get intersection of two linked lists head1 and head2 */
struct node * getIntersection(struct node * head1, struct node * head2) {
  struct node * result = NULL;
  struct node * t1 = head1;

  // Traverse list1 and search each element of it in list2. If the element
  // is present in list 2, then insert the element to result
  while (t1 != NULL) {
    if (isPresent(head2, t1 - > data))
      push( & result, t1 - > data);
    t1 = t1 - > next;
  }

  return result;
}

/* A utility function to insert a node at the begining of a linked list*/
void push(struct node ** head_ref, int new_data) {
  /* allocate node */
  struct node * new_node =
    (struct node * ) malloc(sizeof(struct node));

  /* put in the data */
  new_node - > data = new_data;

  /* link the old list off the new node */
  new_node - > next = ( * head_ref);

  /* move the head to point to the new node */
  ( * head_ref) = new_node;
}

/* A utility function to print a linked list*/
void printList(struct node * node) {
  while (node != NULL) {
    printf(“ % d“, node - > data);
    node = node - > next;
  }
}

/* A utilty function that returns true if data is present in linked list
else return false */
int isPresent(struct node * head, int data) {
  struct node * t = head;
  while (t != NULL) {
    if (t - > data == data)
      return 1;
    t = t - > next;
  }
  return 0;
}
void main() {
  /* Start with the empty list */
  struct node * head1 = NULL;
  struct node * head2 = NULL;
  struct node * intersecn = NULL;
  int n, num, i;
  clrscr();
  /*create a linked lits 10->15->5->20 */
  printf(“\nEnter total number elements of first list: \n”);
  scanf(“ % d”, & n);
  for (i = 0; i < n; i++) {
    printf(“\nenter % d element: “, i + 1);
    scanf(“ % d”, & num);
    push( & head1, num);
  }

  printf(“\nEnter total number elements of second list: \n”);
  scanf(“ % d”, & n);
  for (i = 0; i < n; i++) {
    printf(“\nenter % d element: “, i + 1);
    scanf(“ % d”, & num);
    push( & head2, num);
  }

  intersecn = getIntersection(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);
  getch();
}

Output

Enter total number elements of first list :
5

enter 1 element : 3

enter 2 element : 6

enter 3 element : 9

enter 4 element : 12

enter 5 element : 16

Enter total number elements of second list :
3

enter 1 element : 3

enter 2 element : 6

enter 3 element : 10

First list is
16 12 9 6 3
Second list is
10 6 3
Intersection list is
3 6