Remove loop in Linked List.cpp

// driver code

#include <iostream>
using namespace std;

struct Node
{
    int data;
    Node* next;
    
    Node(int val)
    {
        data = val;
        next = NULL;
    }
};

void loopHere(Node* head, Node* tail, int position)
{
    if(position==0) return;
    
    Node* walk = head;
    for(int i=1; i<position; i++)
        walk = walk->next;
    tail->next = walk;
}

bool isLoop(Node* head)
{
    if(!head) return false;
    
    Node* fast = head->next;
    Node* slow = head;
    
    while( fast != slow)
    {
        if( !fast || !fast->next ) return false;
        fast=fast->next->next;
        slow=slow->next;
    }
    
    return true;
}

int length(Node* head)
{
    int ret = 0;
    while(head)
    {
        ret++;
        head = head->next;
    }
    return ret;
}

void removeLoop(Node* head);

int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        int n, num;
        cin>>n;
        
        Node *head, *tail;
        cin>> num;
        head = tail = new Node(num);
        
        for(int i=0 ; i<n-1 ; i++)
        {
            cin>> num;
            tail->next = new Node(num);
            tail = tail->next;
        }
        
        int pos;
        cin>> pos;
        loopHere(head,tail,pos);
        
        removeLoop(head);
        
        if( isLoop(head) || length(head)!=n )
            cout<<"0\n";
        else
            cout<<"1\n";
    }
	return 0;
}
// } Driver Code Ends


/*
structure of linked list node:

struct Node
{
    int data;
    Node* next;
    
    Node(int val)
    {
        data = val;
        next = NULL;
    }
};

*/
int  checkloop(Node* head)
{
    if(head==NULL)
    return 0;
    
    Node* fast=head,*slow=head;
    while(fast->next!=NULL && fast->next->next!=NULL)
    {
        fast=fast->next->next;
        slow=slow->next;
        if(fast==slow)
        {
            slow=slow->next;
            int count=1;
            while(fast!=slow)
            {
                slow=slow->next;
                count++;
            }
            return count;
        }
        
    }
    return 0;
}
void removeLoop(Node* head)
{
    
    int size=checkloop(head);
    if(size>0)
    {
        Node* t1=head,*t2;
        int count=0;
        while(count<size)
        {
            t1=t1->next;
            count++;
        }
        t2=t1;
        t1=head;
        while(t1!=t2)
        {
            t1=t1->next;
            t2=t2->next;
        }
        while(t2->next!=t1)
        {
            t2=t2->next;
        }
        t2->next=NULL;
       
      
        return;
        
        
    }
    return ;
}