/*NthToLast.java

Nth to Last Node in List

Find the nth to last element of a singly linked list.

The minimum number of nodes in list is n.

Example

Given a List 3->2->1->5->null and n = 2, return node whose value is 1.

Tags Cracking The Coding Interview Linked List

*/

public class NthToLast {

/**

* @param head: The first node of linked list.

* @param n: An integer.

* @return: Nth to last node of a singly linked list.

*/

ListNode nthToLast(ListNode head, int n) {

// write your code here

if (head == null || head.next == null || n <= 0) {

return head;

}

ListNode slow = head;

ListNode fast = head.next;

for (int i = 0; i < n - 1; i++) {

fast = fast.next;

}

while (fast != null) {

slow = slow.next;

fast = fast.next;

}

return slow;

}

}