package leetcode;

import org.junit.Test;

import junit.framework.TestCase;

/**

* Link: https://leetcode.com/problems/rotate-list/

*

* @author shivam.maharshi

*/

public class RotateList extends TestCase {

@Test

public static void test() {

ListNode o = new ListNode(1);

ListNode t = new ListNode(2);

ListNode th = new ListNode(3);

ListNode f = new ListNode(4);

ListNode fi = new ListNode(5);

o.next = t;

t.next = th;

th.next = f;

f.next = fi;

// assertEquals(f, rotateRight(o, 2));

assertEquals(f, rotateRight(o, 7));

}

public static ListNode rotateRight(ListNode head, int k) {

if (head == null)

return head;

int l = 0;

ListNode n = head;

while (n != null) {

n = n.next;

l++;

}

if (k % l == 0)

return head;

k = l - (k % l);

ListNode first = head;

ListNode last = null;

while (k > 0) {

last = first;

first = first.next;

k--;

}

ListNode t = first;

while (t.next != null) {

t = t.next;

}

t.next = head;

last.next = null;

return first;

}

}