public static ListNode ReverseAlternate(ListNode head, int k)
{
var current = head;
ListNode previous = null;
while (current != null)
{
int count = 0;
ListNode next = ReverseKElement.ReverseSub(current, k);
if (previous == null)
{ //if previous is still null then p is the head node
//assign the new head to the output of reverseSub
head = next;
}
else
{
previous.next = next;
}
//Move k Steps
while (current != null && count < k + 1)
{
//keep track of the previous value
previous = current;
current = current.next;
count++;
}
}
return(head);
}
/// <summary>
/// Reserve the linked list in group of k (HARD)
/// </summary>
public static ListNode ReverseNodeInGroupK(ListNode head, int k)
{
var current = head;
ListNode previous = null;
while (current != null)
{
ListNode next = ReverseKElement.ReverseSub(current, k);
if (previous == null)
{ //if previous is still null then p is the head node
//assign the new head to the output of reverseSub
head = next;
}
else
{
previous.next = next;
}
//keep track of the previous value
previous = current;
current = current.next;
}
return(head);
}