//2->10-2->2
public static ListNode removeAllMatchingElements(ListNode head, int val)
{
ListNode current = head;
ListNode Head = head;
ListNode previous = null;
while (current != null)
{
if (current.val.Equals(val))
{
var next = current.next;
if (current.Equals(Head))
{
if (next != null)
{
Head.val = next.val;
Head.next = next.next;
}
else
{
Head = null;
}
current = Head;
previous = null;
}
else
{
if (next != null)
{
current.val = next.val;
current.next = next.next;
}
else
{
previous.next = null;
current = null;
}
}
}
else
{
previous = current;
current = current.next;
}
}
return(Head);
}
public static ListNode FindNodeIntersection(ListNode headA, ListNode headB)
{
ListNode node = null;
int lenA = 0;
int lenB = 0;
var currentA = headA;
var currentB = headB;
while (currentA != null)
{
currentA = currentA.next;
lenA++;
}
while (currentB != null)
{
currentB = currentB.next;
lenB++;
}
if (lenA > lenB)
{
if (lenB > 1)
{
var diff = lenA - lenB;
while (diff != 0)
{
headA = headA.next;
diff--;
}
}
}
if (lenB > lenA)
{
if (lenA > 1)
{
var diff = lenB = lenA;
while (diff != 0)
{
headB = headB.next;
diff--;
}
}
}
while (headA != null && headB != null)
{
if (headA.Equals(headB))
{
node = headA;
break;
}
if (lenA > 1)
{
headA = headA.next;
}
if (lenB > 1)
{
headB = headB.next;
}
}
return(node);
}
public static ListNode RotateLinkedList(ListNode head, int k)
{
ListNode slowPtr = head;
ListNode fastPtr = head;
ListNode last = null;
ListNode previous = null;
if (head == null)
{
return(null);
}
if (k == 0)
{
return(head);
}
int i = 0;
while (true)
{
if (i < k)
{
last = fastPtr;
fastPtr = fastPtr.next;
i++;
}
if (i == k)
{
break;
}
if (fastPtr == null)
{
break;
}
}
if (i < k)
{
k = k % i;
i = 0;
fastPtr = head;
}
if (k == 0)
{
return(head);
}
while (fastPtr != null)
{
if (i < k)
{
fastPtr = fastPtr.next;
i++;
}
else
{
last = fastPtr;
previous = slowPtr;
fastPtr = fastPtr.next;
slowPtr = slowPtr.next;
}
}
if (slowPtr != head)
{
if (slowPtr.Equals(last))
{
previous.next = null;
var next = head.next;
slowPtr.next = head;
head = slowPtr;
}
else
{
previous.next = null;
last.next = head;
head = slowPtr;
}
}
return(head);
}
