need some help turning this single linked list into a circular linked list. I am completly lost on how to get the first node and link it to the last one

#include <iostream>
using namespace std;

struct node
{
	int  Item;
	node* Next;
}; // end struct

node* Head;

typedef node* ptrType;
//====================================================================
void insert_node(ptrType& Head, int value)
{
	ptrType Cur;
	ptrType Prev;
	ptrType NewPtr;
	bool inserted;

	NewPtr = new node;
	NewPtr -> Item = value;
	NewPtr -> Next = NULL;  // just to be on the safe side
		                           
	
	if (Head == NULL) 
		Head = NewPtr; // case 1
	// NewPtr -> Next remains NULL, since
	// this is the list's end
	else if (NewPtr -> Item <= Head -> Item)
	{   // case 2
		NewPtr -> Next = Head;
		Head = NewPtr;
	}
	else
	{ 
		Prev = Head;
		Cur = Head -> Next;
		inserted = false;

		while (Cur != NULL && !inserted)
		{
			if (NewPtr -> Item <= Cur -> Item)
			{  // case 3
				NewPtr -> Next = Cur;
				Prev -> Next = NewPtr;
				inserted = true;
			}
			else
			{
				Prev = Prev -> Next;
				Cur  = Cur -> Next;
			}
		}
		if (!inserted)
		{
			Prev -> Next = NewPtr; // case 4
		}
		// NewPtr -> Next remains NULL,
		// since this is the list's end
	}
}
//==================================================================
void print_circle(ptrType Head)
{
	ptrType current = Head;

	if(Head == NULL)
		cout << "empty list\n";
	else
	{
		while(current != NULL)
		{
			cout << current->Item << endl;
			current = current->Next;
		}
	}
}
//==================================================================
void send_Data()
{
	for (int n = 1;n<10;n++)
		insert_node(Head,n);
}

int main()
{
	send_Data();
	print_circle(Head);

	int g;
	cin >> g;
	return 0;
}

You should add a pointer to the previous node, or keep a pointer to your first node and add that as your "Next" node on your last node.

And once your last node's Next pointer points back to Head, you have to maintain and deal with that.

As far as dealing with it, your print_circle() routine will never end as currently written (current will never become NULL).

As far as maintaining it, you need to address specific cases:
+ what should happen when you add the first node to an empty list?
+ what should happen when a new node is added to the front of the list?
+ what should happen when a new node is added to the end of the list?
+ (as long as the last node already points to Head, adding a new node in the middle of the list should work as currently implemented!)

This article has been dead for over six months. Start a new discussion instead.