// PROGRAM ID: CreateList / Code to create an anchored singly linked list
// REMARKS: This module contains a C++ function, CreateList, that creates
// an "anchored singly-linked list" using values from standard input.
// The items in the list should be in ascending (sorted) order.

#include <iostream>
#include "CreateList.h"
using namespace std;

void insertNode( tNodePtr& head, double num );

void CreateList( tNodePtr& head )
//               OUT
{
	double item;  // Input value to be inserted into linked list

	head = nullptr;
	for (int k=0; k<10; ++k)
	{
		cin >> item;
		insertNode(head, item);
	}
	return;
}


//**************************************************
// The insertNode function inserts a node (inorder)*
// with num copied to its value member.            *
//**************************************************
void insertNode( tNodePtr& head, double num )
//               INOUT           IN
{
	tNodePtr newNode;                  // A new node
	tNodePtr nodePtr;                  // To traverse the list
	tNodePtr previousNode = nullptr;   // The previous node

	// Allocate a new node and store num there.
	newNode = new ListNode;
	newNode->value = num;
   
	// If there are no nodes in the list
	// make newNode the first node
	if (head==nullptr)
	{
		head = newNode;
		newNode->next = nullptr;
	}
	else  // Otherwise, insert newNode
	{
		// Position nodePtr at the head of list.
		nodePtr = head;

		// Initialize previousNode to nullptr.
		previousNode = nullptr;

		// Skip all nodes whose value is less than num.
		while (nodePtr != nullptr && nodePtr->value < num)
		{  
			previousNode = nodePtr;
			nodePtr = nodePtr->next;
		}

		// If the new node is to be the 1st in the list,
		// insert it before all other nodes.
		if (previousNode == nullptr)
		{
			head = newNode;
			newNode->next = nodePtr;
		}
		else  // Otherwise insert after the previous node.
		{
			previousNode->next = newNode;
			newNode->next = nodePtr;
		}
	}
	return;
}