CareerCup

Use two pointers to traverse the link list, the first one move 1 step, second one move 2 steps, when the second pointer reach the end, set the head of the second list to be the next of the first pointer (and also remove the link from the previous pointer)

public node* SplitList(node* head)
{
if(head == null)
{
return;
}
node* p1 = head;
node* p2 = head;

while(p2 != null)
{
p2 = p2->next;
if(p2!=null)
{
p2 = p2->next;
}
p1 = p1->next;
}
node* head2 = p1->next;
p1->next = null;
return head2;
}

Take 2 pointers, move one pointer 2 nodes and other 1 node

In case of 4 nodes
Pointer 1 => pointing to 2 node
Pointer 2 => pointing to 4th node



In case of 5 nodes
Pointer 1 => pointing to 3rd node
Pointer 2 => pointing to NULL.

Point pointer 2 to pointer 1->next

slow=fast=head;
while(fast->next!=NULL && fast->next->next!=NULL)
{
     slow=slow->next;

slow=fast=head;
while(fast->next!=NULL && fast->next->next!=NULL)
{
     slow=slow->next;
     fast=fast->next->next;
}
front=head;
if(slow->next!=NULL)
{
    last=slow->next;
}
else
{
    last=NULL;
}