Given two lists sorted in increasing order, create and return a new list representing the intersection of the two lists. The new list should be made with its own memory — the original lists should not be changed.
For example, let the first linked list be 1->2->3->4->6 and second linked list be 2->4->6->8, then your function should create and return a third list as 2->4->6.
// https://www.geeksforgeeks.org/intersection-of-two-sorted-linked-lists/
#include <bits/stdc++.h>
using namespace std;
struct linked_list {
int data;
struct linked_list* next;
};
typedef struct linked_list node;
void print (node* n) {
while (n != NULL) {
cout<< n->data<< "->";
n = n->next;
}
}
node* insert(node* head, int n) {
if (head == NULL) {
node* list= (node*)malloc(sizeof(node*));
list->data = n;
list->next = NULL;
head = list;
return head;
}
node* list= (node*)malloc(sizeof(node*));
list->data = n;
list->next = NULL;
node* last= head;
while (last->next != NULL )
last = last->next;
last->next = list;
return head;
}
node* intersection (node *head1, node *head2) {
node* head3 = NULL;
while (head1 && head2) {
if (head1->data == head2->data) {
head3 = insert(head3, head1->data);
head1 = head1->next;
head2 = head2->next;
}
else if (head1->data < head2->data)
head1 = head1->next;
else if (head1->data > head2->data)
head2 = head2->next;
}
return head3;
}
int main() {
int n;
node* head1 = NULL, *head2=NULL;
cout<< "Enter the first list: \n";
while (true) {
cout<< "Enter the elements, and -999 to stop: ";
cin>>n;
if (n==-9)
break;
else
head1=insert(head1,n);
}
cout<< "Enter the second list: \n";
while (true) {
cout<< "Enter the elements, and -999 to stop: ";
cin>>n;
if (n==-9)
break;
else
head2=insert(head2,n);
}
print(head1);
cout << "\n";
print(head2);
cout << "\n";
node* head3 = intersection(head1,head2);
print(head3);
}