static void FindStartOfLoop(Node node)
{
Node slow = node;
Node fast = node;
while (fast.next != null)
{
fast = fast.next.next;
slow = slow.next;
if (slow == fast)
break;
}
if (fast == null)
{
Console.WriteLine("There is no loop");
return;
}
Console.WriteLine("Slow/Fast meeting point: {0}", fast.data);
slow = node;
while (slow != fast && fast != null)
{
slow = slow.next;
fast = fast.next;
}
Console.WriteLine("Start of loop node: {0}", slow.data);
}
public static void GetNthFromEnd(Node node, int n)
{
if (n <= 0 || node == null)
return;
Node fast = node;
Node slow = node;
for (int i = 0; i < n; i++)
{
if (fast != null)
fast = fast.next;
else
{
Console.WriteLine("Invalid n");
return;
}
}
while (fast != null)
{
fast = fast.next;
slow = slow.next;
}
Console.WriteLine("Nth from last = {0}", slow.data);
}
public static void printList(Node node)
{
Console.Write("List: ");
while (node != null)
{
Console.Write("{0} ", node.data);
node = node.next;
}
}
static void deleteNode(Node n)
{
if (n == null || n.next == null)
return;
if (n.next != null)
{
n.data = n.next.data;
n.next = n.next.next;
}
}
public Node buildList(int size)
{
Node cur;
for (int i = size; i >= 1; i--)
{
cur = new Node(i);
cur.next = head;
head = cur;
}
return head;
}
public Node buildList(int[] arr)
{
Node cur;
foreach (int i in arr)
{
cur = new Node(i);
cur.next = head;
head = cur;
}
return head;
}
static void RemoveDuplicates(Node node)
{
if (node == null)
return;
HashSet<int> hs = new HashSet<int>();
hs.Add(node.data);
while (node.next != null)
{
if (hs.Contains(node.next.data))
{
node.next = node.next.next;
}
else
{
node = node.next;
hs.Add(node.data);
}
}
}
static Node AddLists(Node a, Node b)
{
Node dummy = new Node(-1);
Node sum = dummy;
int carry = 0;
while (a != null && b != null)
{
int val = a.data + b.data + carry;
Node cur = new Node(val % 10);
carry = val / 10;
sum.next = cur;
sum = cur;
a = a.next;
b = b.next;
}
while (a != null)
{
int val = a.data + carry;
Node cur = new Node(val % 10);
carry = val / 10;
sum.next = cur;
sum = cur;
a = a.next;
}
while (b != null)
{
int val = b.data + carry;
Node cur = new Node(val % 10);
carry = val / 10;
sum.next = cur;
sum = cur;
b = b.next;
}
if (carry > 0)
sum.next = new Node(carry);
return dummy.next;
}
public Node(int data, Node next)
{
this.data = data;
this.next = next;
}