Getting Kth element from last of Linked-List

// to find the kth element from the last of the linked list
#include<iostream>
#include<conio.h>
using namespace std;
struct node
{
    int data;
    node *link;
}*head=NULL,*ptr;
int n=0;
int create()
{
   
    int value;
    cout<<"enter the data you want to enter in the linked list"<<endl;
    cin>>value;
    ptr=head;
    if(head==NULL)
    {
        ptr=new node;
        ptr->data=value;
        ptr->link=NULL;
        head=ptr;
        n++;
    }
    else
    {
        ptr=new node;
        ptr->data=value;
        ptr->link=head;
        head=ptr;
        n++;
    }
    return n;
}

void display()
{
    ptr=head;
    while(ptr!=NULL)
    {
        cout<<ptr->data<<"\t";
        ptr=ptr->link;
    }
    cout<<endl;
}

void find()
{
    int k;
    cout<<"enter the value of k"<<endl;
    cout<<"i.e enter the position of the element from the last"<<endl;
    cin>>k;
    int c=(n-k)+1;
    int c1=1;
    ptr=head;
    while(c1!=c)
    {
        c1++;
        ptr=ptr->link;
    }
    cout<<endl;
    cout<<"the kth element from the end is"<<endl;
    cout<<ptr->data<<endl;
    cout<<endl;
}

int main()
{
    int option;
    while(option!=4)
    {
    cout<<"enter 1. to insert"<<endl;
    cout<<"enter 2. to display"<<endl;
    cout<<"enter 3. to find"<<endl;
    cout<<"enter 4. to exit"<<endl;
    cin>>option;
    switch(option)
    {
        case 1: create();
        break;
        case 2: display();
        break;
        case 3: find();
        break;
    }
    }
    getch();
    return 0;
}




OUTPUT:--