Simple C Program to get the kth node from last in a linked list

This can be done in single traversal using two pointers . First move to the kth node from first and point it using temp pointer . Point the head node using another pointer called kthnodefromlast .Now Move the temp pointer and kthnodefromlast to next node till temp node reaches the end of the linked list.

Example:

 1->2->3->4->5->6->7->NULL

 For the above linked list kth(k=3) node from last is 5.

 Code:(in C)

	struct node* getKthNodeFromLast(struct node* head , int k)
	{
	if(head==null || k<1)
	return null;
	struct node* temp=head,*kthnodefromlast=head;
	while(--k>0)
	{
	temp=temp->link;
	if(temp==null)
	return null;
	}
	while((temp=temp->link)!=null)
	kthnodefromlast=kthnodefromlast->link;
	return kthnodefromlast;
	}

view raw kthfromlast.c hosted with ❤ by GitHub

Time Complexity : O(n)
Space Complexity: O(1)

 Please let me know if you have any questions .