//O(a+b) time, O(1) space
static LinkListNode getIntersect(LinkListNode n1, LinkListNode n2)
{
LinkListNode head1 = n1;
LinkListNode head2 = n2;
TailAndSize s1 = getTailandSize(n1);
TailAndSize s2 = getTailandSize(n2);
if (s1.Tail == s2.Tail)
{
LinkListNode longer = s1.Size > s2.Size ? head1 : head2;
LinkListNode shorter = s1.Size < s2.Size ? head1 : head2;
longer = getKthNode(longer, Math.Abs(s1.Size - s2.Size));
while (longer != shorter) {
longer = longer.next;
shorter = shorter.next;
}
return longer;
}
else
return null;
}
public void setPrevious(LinkListNode p)
{
prev = p;
if (p != null && p.next != this)
{
p.setNext(this);
}
}
static LinkListNode getKthNode(LinkListNode node, int k)
{
while (k > 0) {
node = node.next;
k--;
}
return node;
}
static TailAndSize getTailandSize(LinkListNode node)
{
int i = 1;
while(node.next != null){
++i;
node = node.next;
}
return new TailAndSize(node, i);
}
static LinkListNode getKthNode(LinkListNode node, int k)
{
while (k > 0)
{
node = node.next;
k--;
}
return(node);
}
public LinkListNode clone()
{
LinkListNode next2 = null;
if (next != null)
{
next2 = next.clone();
}
LinkListNode head2 = new LinkListNode(data, next2, null);
return head2;
}
public LinkListNode clone()
{
LinkListNode next2 = null;
if (next != null)
{
next2 = next.clone();
}
LinkListNode head2 = new LinkListNode(data, next2, null);
return(head2);
}
public void setNext(LinkListNode n)
{
next = n;
if (this == last)
{
last = n;
}
if (n != null && n.prev != this)
{
n.setPrevious(this);
}
}
static TailAndSize getTailandSize(LinkListNode node)
{
int i = 1;
while (node.next != null)
{
++i;
node = node.next;
}
return(new TailAndSize(node, i));
}
public void setNext(LinkListNode n)
{
next = n;
if (this == last)
{
last = n;
}
if (n != null && n.prev != this)
{
n.setPrevious(this);
}
}
//determing if 2 lists intersect, return the intersecting node.
static void Main(string[] args)
{
//0 -> 1 -> 2 -> 3 -> 6 -> 7
// 5 -> 4 -> 3 -> 6 -> 7
LinkListNode n1 = new LinkListNode(0);
n1.next = new LinkListNode(1);
n1.next.next = new LinkListNode(2);
LinkListNode n2 = new LinkListNode(5);
n2.next = new LinkListNode(4);
LinkListNode intersect = new LinkListNode(3);
n1.next.next.next = intersect;
n2.next.next = intersect;
intersect.next = new LinkListNode(6);
intersect.next.next = new LinkListNode(7);
Console.WriteLine(n1.printForward());
Console.WriteLine(n2.printForward());
if (getIntersect(n1, n2) != null)
Console.WriteLine(getIntersect(n1, n2).printForward());
else
Console.WriteLine("not intersacted");
LinkListNode n1notintersact = new LinkListNode(0);
n1notintersact.next = new LinkListNode(1);
n1notintersact.next.next = new LinkListNode(2);
n1notintersact.next.next.next = new LinkListNode(3);
n1notintersact.next.next.next.next = new LinkListNode(6);
n1notintersact.next.next.next.next.next = new LinkListNode(7);
LinkListNode n2notintersact = new LinkListNode(5);
n2notintersact.next = new LinkListNode(4);
n2notintersact.next.next = new LinkListNode(3);
n2notintersact.next.next.next = new LinkListNode(6);
n2notintersact.next.next.next.next = new LinkListNode(7);
Console.WriteLine(n1notintersact.printForward());
Console.WriteLine(n2notintersact.printForward());
if (getIntersect(n1notintersact, n2notintersact) != null)
Console.WriteLine(getIntersect(n1notintersact, n2notintersact).printForward());
else
Console.WriteLine("not intersacted");
}
public TailAndSize(LinkListNode tail, int size)
{
this.Tail = tail;
this.Size = size;
}
public TailAndSize(LinkListNode tail, int size)
{
this.Tail = tail;
this.Size = size;
}
public LinkListNode(int d, LinkListNode n, LinkListNode p)
{
data = d;
setNext(n);
setPrevious(p);
}
{//determing if 2 lists intersect, return the intersecting node.
static void Main(string[] args)
{
//0 -> 1 -> 2 -> 3 -> 6 -> 7
// 5 -> 4 -> 3 -> 6 -> 7
LinkListNode n1 = new LinkListNode(0);
n1.next = new LinkListNode(1);
n1.next.next = new LinkListNode(2);
LinkListNode n2 = new LinkListNode(5);
n2.next = new LinkListNode(4);
LinkListNode intersect = new LinkListNode(3);
n1.next.next.next = intersect;
n2.next.next = intersect;
intersect.next = new LinkListNode(6);
intersect.next.next = new LinkListNode(7);
Console.WriteLine(n1.printForward());
Console.WriteLine(n2.printForward());
if (getIntersect(n1, n2) != null)
{
Console.WriteLine(getIntersect(n1, n2).printForward());
}
else
{
Console.WriteLine("not intersacted");
}
LinkListNode n1notintersact = new LinkListNode(0);
n1notintersact.next = new LinkListNode(1);
n1notintersact.next.next = new LinkListNode(2);
n1notintersact.next.next.next = new LinkListNode(3);
n1notintersact.next.next.next.next = new LinkListNode(6);
n1notintersact.next.next.next.next.next = new LinkListNode(7);
LinkListNode n2notintersact = new LinkListNode(5);
n2notintersact.next = new LinkListNode(4);
n2notintersact.next.next = new LinkListNode(3);
n2notintersact.next.next.next = new LinkListNode(6);
n2notintersact.next.next.next.next = new LinkListNode(7);
Console.WriteLine(n1notintersact.printForward());
Console.WriteLine(n2notintersact.printForward());
if (getIntersect(n1notintersact, n2notintersact) != null)
{
Console.WriteLine(getIntersect(n1notintersact, n2notintersact).printForward());
}
else
{
Console.WriteLine("not intersacted");
}
}
public LinkListNode(int d, LinkListNode n, LinkListNode p)
{
data = d;
setNext(n);
setPrevious(p);
}
