CareerCup

You can maintain three variable to store the top 3 elements while sweeping the list.

1. Start one pointer "fp" and iterate through linkedlist until it reaches 3rd node.
2. When "fp" reaches 3rd element, start another pointer "sp" from head node.
3. From now on, advance both pointers"fp" and "sp", node by node until you reach "fp"pointing to NULL.
4. At this time "sp" is pointing to 3rd element from end of the linked list
5. In other words, iterating a pointer to maintain some gap (here 3 in this example)

check if the node->next->next->next is null..if so, then you are at the n-3 rd element.

I don't think you need 3 temps, 2 are sufficient, one t1 = head->next->next->next, and t2 = head.
Make ++t1, and ++t2, until t1 == NULL.

public Link find(Link first)
{
Link current =first;
Link fast=first;
while (fast !=null)
{
fast=fast.next.next.next;
current=current.next;
}
return current;
}

Hi

Node* findNthToLast(Node* head, int n)
{
	Node* temp = head;
	Node* nthToLast = NULL;
	int count = 0;
	while(temp != NULL)
		{
			count++;
			temp = temp->next
			if(count == n)
			{
				nthToLast = head;
			}
			else if (count > n)
			{
				nthToLast = nthToLast ->next;
			}

		}
		if(nthToLast == NULL)
		{
			cout << "Error: List size is smaller than N"<<endl;
		}
		return nthToLast;
}

public void getNthMinusyElement(int n){
System.out.println();
ListNode curr = head;
ListNode nthToLast = null;
int count = 0;
while(curr != null)
{
count++;
curr = curr.getNext();
if(count == n)
{
nthToLast = head;
}
else if (count > n)
{
nthToLast = nthToLast.getNext();
System.out.println("data==="+nthToLast.getData());

}

}
System.out.println(nthToLast.getData());

}

class Node:
    def __init__(self, data, next= None):
        self.data=data
        self.next = next

class LinkList:
    def __init__(self):
        self.head = None
    def show_value(self, node_obj):
        if node_obj:
            return f'Data:{node_obj.data}, Next:{node_obj.next}'
    def add_values(self, node_data):
        if not self.head:
            self.head = Node(data=node_data)
            return self.head
        temp = self.head
        while temp.next:
            temp = temp.next
        temp.next = Node(data=node_data)
        return temp.next

    def find_third_last(self):
        if not self.head:
            return None
        elif not self.head.next.next:
            return "Need atleast three elements in list"
        pointer2 = self.head.next.next
        pointer1 = self.head
        while pointer2.next is not None:
            pointer1 = pointer1.next
            pointer2 = pointer2.next
        return self.show_value(pointer1)
x = LinkList()
for i in range(10,90):
    x.add_values(i)
print(x.find_third_last())