(LINKEDLIST)checkingintersectionof2linkedlist(method2.cpp)

// CPP program to print intersection of lists
#include <bits/stdc++.h>
using namespace std;

/* Link list node */
class Node {
public:
	int data;
	Node* next;
};

// A utility function to return intersection node
Node* intersectPoint(Node* head1, Node* head2)
{
	// Maintaining two pointers ptr1 and ptr2
	// at the head of A and B,
	Node* ptr1 = head1;
	Node* ptr2 = head2;

	// If any one of head is NULL i.e
	// no Intersection Point
	if (ptr1 == NULL || ptr2 == NULL) {

		return NULL;
	}

	// Traverse through the lists until they
	// reach Intersection node
	while (ptr1 != ptr2) {

		ptr1 = ptr1->next;
		ptr2 = ptr2->next;

		// If at any node ptr1 meets ptr2, then it is
		// intersection node.Return intersection node.

		if (ptr1 == ptr2) {

			return ptr1;
		}
		/* Once both of them go through reassigning,
		they will be equidistant from the collision point.*/

		// When ptr1 reaches the end of a list, then
		// reassign it to the head2.
		if (ptr1 == NULL) {

			ptr1 = head2;
		}
		// When ptr2 reaches the end of a list, then
		// redirect it to the head1.
		if (ptr2 == NULL) {

			ptr2 = head1;
		}
	}

	return ptr1;
}

// Function to print intersection nodes
// in a given linked list
void print(Node* node)
{
	if (node == NULL)
		cout << "NULL";
	while (node->next != NULL) {
		cout << node->data << "->";
		node = node->next;
	}
	cout << node->data;
}
// Driver code
int main()
{
	/*
	Create two linked lists

	1st Linked list is 3->6->9->15->30
	2nd Linked list is 10->15->30

	15 30 are elements in the intersection list
	*/

	Node* newNode;
	Node* head1 = new Node();
	head1->data = 10;
	Node* head2 = new Node();
	head2->data = 3;
	newNode = new Node();
	newNode->data = 6;
	head2->next = newNode;
	newNode = new Node();
	newNode->data = 9;
	head2->next->next = newNode;
	newNode = new Node();
	newNode->data = 15;
	head1->next = newNode;
	head2->next->next->next = newNode;
	newNode = new Node();
	newNode->data = 30;
	head1->next->next = newNode;
	head1->next->next->next = NULL;
	Node* intersect_node = NULL;

	// Find the intersection node of two linked lists
	intersect_node = intersectPoint(head1, head2);

	cout << "INTERSEPOINT LIST :";

	print(intersect_node);

	return 0;
// This code is contributed by bolliranadheer
}