/*

structure of linked list node:

struct Node

{

    int data;

    Node* next;

    Node(int val)

    {

        data = val;

        next = NULL;

    }

};

*/

class Solution

{

    public:

    //Function to remove a loop in the linked list.

    void removeLoop(Node* head)

    {

        // code here

        // just remove the loop without losing any nodes

        // if(head==NULL||head->next==NULL)return;

        Node *fast = head;

        Node *slow = head;

        while(fast!=NULL&&fast->next!=NULL){

            slow = slow->next;

            fast= fast->next->next;

            if(slow==fast)break;

        }

        if(slow!=fast)return;

        slow = head;

        while(slow!=fast){

            slow=slow->next;

            fast = fast->next;

        }

             while(slow!=fast->next){

          fast=fast->next;

             }

        fast->next=NULL;

    }

};