public ListNode PartitionList(ListNode node, int x)
{
ListNode head = node;
ListNode tail = node;
/* Partition list */
while (node != null)
{
ListNode next = node.Next;
if (node.Data < x)
{
/* Insert node at head. */
node.Next = head;
head = node;
}
else
{
/* Insert node at tail. */
tail.Next = node;
tail = node;
}
node = next;
}
tail.Next = null;
return head;
}
public void DeleteListNode(ListNode node)
{
// tail node
if (node.Next == null) return;
ListNode temp = node.Next;
node.Data = temp.Data;
node.Next = temp.Next;
}
public void Delete_Duplicates()
{
ListNode l1 = new ListNode(1);
l1.Next = new ListNode(1);
l1.Next.Next = new ListNode(2);
ListNode r1 = DeleteDuplicates(l1);
Assert.AreEqual(r1.Data, 1);
Assert.AreEqual(r1.Next.Data, 2);
}
public void Reverse_Linked_List()
{
ListNode list = new ListNode(1);
list.Next = new ListNode(2);
list.Next.Next = new ListNode(3);
ListNode result = ReverseList(list);
Assert.AreEqual(result.Data, 3 );
Assert.AreEqual(result.Next.Data, 2);
Assert.AreEqual(result.Next.Next.Data, 1);
}
public void Delete_Linked_List_Node()
{
ListNode l = new ListNode(1);
l.Next = new ListNode(2);
ListNode thirdNode = l.Next.Next = new ListNode(3);
l.Next.Next.Next = new ListNode(4);
DeleteListNode(thirdNode);
Assert.AreEqual(l.Data, 1);
Assert.AreEqual(l.Next.Data, 2);
Assert.AreEqual(l.Next.Next.Data, 4);
}
public ListNode ReverseList(ListNode head)
{
ListNode prev = null;
ListNode curr = null;
ListNode next = head;
while (next != null)
{
curr = next;
next = curr.Next;
curr.Next = prev;
prev = curr;
}
return curr;
}
public ListNode DeleteDuplicates(ListNode head)
{
if (head == null || head.Next == null)
return head;
ListNode p = head;
while (p != null && p.Next != null)
{
if (p.Data == p.Next.Data)
p.Next = p.Next.Next;
else
p = p.Next;
}
return head;
}
public void Partition_List()
{
ListNode head = new ListNode(5);
head.Next = new ListNode(4);
head.Next.Next = new ListNode(3);
head.Next.Next.Next = new ListNode(2);
head.Next.Next.Next.Next = new ListNode(1);
head.Next.Next.Next.Next.Next = new ListNode(0);
ListNode result = PartitionList(head, 3);
Assert.AreEqual(result.Data, 0);
Assert.AreEqual(result.Next.Data, 1);
Assert.AreEqual(result.Next.Next.Data, 2);
Assert.AreEqual(result.Next.Next.Next.Data, 5);
Assert.AreEqual(result.Next.Next.Next.Next.Data, 4);
Assert.AreEqual(result.Next.Next.Next.Next.Next.Data, 3);
}
private ListNode AddTwoList2(ListNode l1, ListNode l2)
{
int carry = 0;
ListNode l3 = null, head = null;
while (l1 != null || l2 != null)
{
if (l1 != null)
{
carry += l1.Data;
l1 = l1.Next;
}
if (l2 != null)
{
carry += l2.Data;
l2 = l2.Next;
}
if (head == null)
{
head = new ListNode(carry%10);
l3 = head;
}
else
{
l3.Next = new ListNode(carry%10);
l3 = l3.Next;
}
carry /= 10;
}
if (carry == 1)
if (l3 != null) l3.Next = new ListNode(1);
return head;
}
private ListNode AddTwoList(ListNode l1, ListNode l2, int carry)
{
if(l1 == null && l2 == null && carry == 0)
{
return null;
}
ListNode result = new ListNode(carry);
int value = carry;
if (l1 != null) value += l1.Data;
if (l2 != null) value += l2.Data;
result.Data = value % 10;
if (l1 != null || l2 != null)
{
ListNode more = AddTwoList(l1?.Next, l2?.Next, value >= 10 ? 1 : 0);
result.Next = more;
}
return result;
}
public void Sum_Two_List()
{
ListNode l1 = new ListNode(2);
l1.Next = new ListNode(4);
l1.Next.Next = new ListNode(3);
ListNode l2 = new ListNode(5);
l2.Next = new ListNode(6);
l2.Next.Next = new ListNode(4);
// for 1st method
ListNode result = AddTwoList(l1, l2);
Assert.AreEqual(7, result.Data);
Assert.AreEqual(0, result.Next.Data);
Assert.AreEqual(8, result.Next.Next.Data);
// for 2nd method
ListNode result2 = AddTwoList2(l1, l2);
Assert.AreEqual(7, result2.Data);
Assert.AreEqual(0, result2.Next.Data);
Assert.AreEqual(8, result2.Next.Next.Data);
}
public ListNode AddTwoList(ListNode l1, ListNode l2)
{
return AddTwoList(l1, l2, 0);
}