static Node addListsReverse(Node n1, Node n2)
{
int length1 = 0;
int length2 = 0;
Node r1 = n1;
Node r2 = n2;
while (r1 != null)
{
length1++;
r1 = r1.next;
}
while (r2 != null)
{
length2++;
r2 = r2.next;
}
n2 = pad(length1, length2, n1, n2);
n1 = pad(length2, length1, n2, n1);
NodeWrapper result = addReverseRecur(n1, n2);
if (result.carry == 1)
{
Node nn = new Node(1);
nn.next = result.n;
return nn;
}
else
{
return result.n;
}
}
static void delete(Node n)
{
if (n == null || n.next == null)
return;
n.data = n.next.data;
n.next = n.next.next;
}
static Node addLists(Node n1, Node n2, bool carry)
{
if (n1 == null && n2 == null && !carry)
return null;
int result = 0;
if (n1 != null)
result += n1.data;
if (n2 != null)
result += n2.data;
if (carry)
result++;
if (result >= 10)
{
carry = true;
result -= 10;
}
else
carry = false;
Node n = new Node(result);
n.next = addLists(n1 == null ? null : n1.next, n2 == null ? null : n2.next, carry);
return n;
}
void appendToTail(int d)
{
Node end = new Node(d);
Node n = this;
while (n.next != null)
n = n.next;
n.next = end;
}
public static void printNodes(Node head)
{
while (head != null)
{
Console.Write(head.data);
Console.Write(" -> ");
head = head.next;
}
Console.Write("null\n");
}
public static Node createLinkedList(int[] nums)
{
Node n = new Node(nums[0]);
Node head = n;
for (int i = 1; i < nums.Length; i++)
{
Node next = new Node(nums[i]);
n.next = next;
n = next;
}
return head;
}
static void removeDuplicateNoStorage(Node n)
{
Node current = n;
while (current != null)
{
Node runner = current;
while (runner.next != null)
{
if (current.data == runner.next.data)
runner.next = runner.next.next;
else
runner = runner.next;
}
current = current.next;
}
}
static NodeWrapper addReverseRecur(Node n1, Node n2)
{
if (n1 == null && n2 == null)
return new NodeWrapper(0, null);
NodeWrapper wrapper = addReverseRecur(n1.next, n2.next);
int result = wrapper.carry + n1.data + n2.data;
int carry = 0;
if (result >= 10)
{
result -= 10;
carry = 1;
}
Node current = new Node(result);
current.next = wrapper.n;
return new NodeWrapper(carry, current);
}
static int kthToLast(int k, Node head)
{
Node current = head;
Node runner = head;
for (int i = 0; i < k; i++)
{
if (runner == null)
return -1;
runner = runner.next;
}
if (runner == null)
return -1;
while (runner.next != null)
{
runner = runner.next;
current = current.next;
}
return current.data;
}
static void removeDuplicate(Node n)
{
HashSet<int> set = new HashSet<int>();
Node next = n.next;
if(next == null)
return;
set.Add(n.data);
while (next != null)
{
if (set.Contains(next.data))
{
n.next = next.next;
}
else
{
set.Add(next.data);
n = n.next;
}
next = next.next;
}
}
static Node getLoopBeginning(Node head)
{
Node fast = head;
Node slow = head;
while (fast != null && fast.next != null)
{
slow = slow.next;
fast = fast.next.next;
if (slow == fast)
break;
}
if (fast == null || fast.next == null)
return null;
slow = head;
while (slow != fast)
{
slow = slow.next;
fast = fast.next;
}
return fast;
}
static Boolean isPalindrome(Node n)
{
Node fastRunner = n;
Node slowRunner = n;
Stack<int> stack = new Stack<int>();
while (fastRunner != null && fastRunner.next != null)
{
fastRunner = fastRunner.next.next;
stack.Push(slowRunner.data);
slowRunner = slowRunner.next;
}
if (fastRunner != null && fastRunner.next == null)//Odd number of nodes
if (stack.Count > 0)//Check case of only one node
stack.Pop();
while (stack.Count > 0)
{
int num = stack.Pop();
if (num != slowRunner.data)
return false;
slowRunner = slowRunner.next;
}
return true;
}
static Node pad(int r1, int r2, Node n1, Node n2)
{
if (r1 <= r2)
return n2;
int diff = r1 - r2;
Node padding = new Node(0);
Node paddingHead = padding;
for (int i = 1; i < diff; i++)
{
padding.next = new Node(0);
padding = padding.next;
}
padding.next = n2;
return paddingHead;
}
public NodeWrapper(int carry, Node n)
{
this.carry = carry;
this.n = n;
}