#include <iostream>

struct node
{
	node	*next;
	int		value;

	node (int i)
	{
		value = i;
	}
};

/**
* Print the addresses and values of each node starting with p.
*
* @param p The address of the first node in the list to print.
********************************************************************/
static void print_list(node *p)
{
	
	std::cout << "************ list **************" << std::endl;

	while(p)
	{
		std::cout << "node: " << p << std::endl;		// print the address of the node
		std::cout << "   next=" << p->next << std::endl;
		std::cout << "  value=" << p->value << std::endl;

		p = p->next;	// prepare to print the 'next' node
	}
}


/**
* Insert a node into the head of the list.
*
* @param phead	A pointer to the head pointer.
* @param p		A pointer to the node to insert.
*****************************************************************/
static void insert_front(node **phead, node *p)
{
	p->next = *phead;
	*phead = p;
}

/**
* Insert a node into the list after the node given by prev.
*
* @param prev	A pointer to the node to insert after.
* @param p		A pointer to the node to insert.
*****************************************************************/
static void insert_after(node *prev, node *p)
{
	p->next = prev->next;
	prev->next = p;
}


/**
* Demonstrate singly-linked list insertions.
*****************************************************************/
int main()
{
	node *phead = nullptr;

	print_list(phead);

	std::cout << "*** insert a new node into an empty list" << std::endl;
	node *pn1 = new node(1);
	insert_front(&phead, pn1);
	print_list(phead);		// 1


	std::cout << "*** insert a new node at the head of a non-empty list" << std::endl;
	node *pn2 = new node(2);
	insert_front(&phead, pn2);
	print_list(phead);		// 2 -> 1


	std::cout << "*** insert a new node at the tail of a non-empty list (after #1)" << std::endl;
	node *pn3 = new node(3);
	insert_after(pn1, pn3);
	print_list(phead);		// 2 -> 1 -> 3


	std::cout << "*** insert a new node into the middle of the list after node #1" << std::endl;
	node *pn4 = new node(4);
	insert_after(pn1, pn4);
	print_list(phead);		// 2 -> 1 -> 4 -> 3

	return 0;
}