public ListNode RotateRight(ListNode head, int k)
{
ListNode newHead = null;
while (k != 0)
{
while (head != null)
{
if (head.next.next == null)
{
newHead = head.next;
head.next = null;
head = newHead;
}
head = head.next;
}
k--;
}
return(head.next);
}
public ListNode RemoveElements(ListNode head, int val)
{
while (head != null && head.val == val)
{
head = head.next;
}
ListNode curr = head;
while (curr != null && curr.next != null)
{
if (curr.next.val == val)
{
curr.next = curr.next.next;
}
else
{
curr = curr.next;
}
}
return(head);
}
public ListNode AddTwoNumbers(ListNode l1, ListNode l2)
{
ListNode head = new ListNode(0);
ListNode res = head;
int carry = 0;
while (l1 != null || l2 != null)
{
int l1_val = (l1.val != null) ? l1.val : 0;
int l2_val = (l2.val != null) ? l2.val : 0;
int current_sum = l1_val + l2_val + carry;
int last_digit = current_sum / 10;
carry = current_sum / 10;
ListNode new_node = new ListNode(last_digit);
res.next = new_node;
if (l1 != null)
{
l1 = l1.next;
}
if (l2 != null)
{
l2 = l2.next;
}
res = res.next;
}
if (carry > 0)
{
ListNode new_node = new ListNode(carry);
res.next = new_node;
res = res.next;
}
return(head.next);
}
public ListNode GetIntersectionNode(ListNode headA, ListNode headB)
{
List <ListNode> visited = new List <ListNode>();
while (headA != null)
{
visited.Add(headA);
headA = headA.next;
}
while (headB != null)
{
if (visited.Contains(headB))
{
return(headB);
}
headB = headB.next;
}
return(null);
}
public ListNode AddTwoNumbersExtra(ListNode l1, ListNode l2)
{
List <int> list1 = new List <int>();
List <int> list2 = new List <int>();
while (l1 != null)
{
list1.Add(l1.val);
l1 = l1.next;
}
while (l2 != null)
{
list2.Add(l2.val);
l2 = l2.next;
}
list1.Reverse();
list2.Reverse();
long sum = Int64.Parse(String.Join("", list1)) + Int64.Parse(String.Join("", list2));
if (sum == 0)
{
return(new ListNode(0));
}
ListNode head = new ListNode(0);
ListNode res = head;
while (sum != 0)
{
res.next = new ListNode((int)sum % 10);
sum = sum / 10;
res = res.next;
}
return(head.next);
}
public ListNode DeleteDuplicates(ListNode head)
{
if (head == null || head.next == null)
{
return(head);
}
ListNode p = head;
while (p != null && p.next != null)
{
if (p.val == p.next.val)
{
p.next = p.next.next;
}
else
{
p = p.next;
}
}
return(head);
}
public ListNode OddEvenList(ListNode head)
{
ListNode init = head;
ListNode res = new ListNode(0);
ListNode resNode = res;
int idx = 1;
while (init != null)
{
if (idx % 2 == 1)
{
resNode.next = new ListNode(init.val);
resNode = resNode.next;
}
init = init.next;
idx++;
}
init = head;
idx = 1;
while (init != null)
{
if (idx % 2 == 0)
{
resNode.next = new ListNode(init.val);
resNode = resNode.next;
}
init = init.next;
idx++;
}
resNode.next = null;
return(res.next);
}
public ListNode RemoveNthFromEnd(ListNode head, int n)
{
ListNode start = new ListNode(0);
ListNode slow = start;
ListNode fast = start;
slow.next = head;
//Move fast in front so that the gap between slow and fast becomes n
for (int i = 1; i <= n + 1; i++)
{
fast = fast.next;
}
//Move fast to the end, maintaining the gap
while (fast != null)
{
slow = slow.next;
fast = fast.next;
}
//Skip the desired node
slow.next = slow.next.next;
return(start.next);
}
