Nth to Last Element in a Single Linked List

HI,
QUESTION: Return the Nth to last Element in a Single Linked List ?

Answer :

Example : Below is the Sample Linked List.

[0] [1] [2] [3] [4] ----> Direction

1 -> 2 -> 3 -> 4 -> 5

[4] [3] [2] [1] [0] <----- Direction.

Now return the Nth element from the end of the linked list.

i.e, if N = 2 /* Return 2nd Index element from the last. i.e., = 3 */

if N = 1 /* Return 4 that, it is 1st element from the last of list*/

if N = 3 /* return 2 that it is 3rd element from the last of linked list.*/

Solution :

Take 2 pointers one points to Head, and move the next pointer to n locations in linked list.

Example : if N = 3

Pointer 1 = points to Head.

Pointer 2 = points to element '4' in the linked list because that has the index = 3. in

the forward Direction.

Code :

Node *pointer2, * pointer1;

pointer1 = head;

while(i = 0 ; i next;

Now increment the both pointers by one by one when

when Pointer2 points to last element in the linked list, then the pointer 1 points to the nth element from the end of the list.