#include<iostream>
 
#include "linkedList.h"
 
//so all functions can use LinkedList class
LinkedList list;
 
void enterNumbers();
void displayList();
void searchList(double z);
void deleteNode(double z);
 
// start main
int main()
{
    // declare variables
	int statusChoice = 0;
	int menuChoice = 0;
	double searchValue = 0.0;
 
 
	// output user information
    cout << "This program uses a linked list. The user has the options to \n";
	cout << "add data to the list, delete data from the list, or display \n";
	cout << "the contents of the list.\n\n\n";
 
	// User input to start or stop the program
	cout << "Linked list operations.\n";
	cout << "Enter 1 to start or 2 to stop.\n" << endl;
	cin >> statusChoice;
	while (statusChoice == 1)
	{	
		//User needs to choose option of what to do
		cout << "Choose an option below" << endl;
		cout << "\t1) Add Data" << endl;
		cout << "\t2) Delete Data" << endl;
		cout << "\t3) Display Data" << endl;
		cout << "\t4) Search" << endl;
		cout << "\t5) Exit" << endl;
		cin >> menuChoice;
 
		switch(menuChoice)
		{
			case 1: enterNumbers();
				break;
			case 2: deleteNode(searchValue);
				break;
			case 3: displayList();
				break;
			case 4: searchList(searchValue);
				break;
			case 5: statusChoice = 2;
		}
	}
 
	// output termination message
	cout << "\n\n\nProgram has terminated successfully!\n\n\n\n";
	return 0;
}
 
void enterNumbers()
{
	double number = 0.0;
 
	// Get input from user and add them to list
	cout << "\nYou now need to enter numbers into the list.";
 
	// enter numbers into the list - entering -1 will escape out of loop
	do
	{   
		cout << "\nEnter a numerical value <Enter -1 to stop>\n";
		cin >> number;
		list.add(number);
	}while(number != -1);
 
}
 
void displayList()
{
	// Print the list
	cout << "\n\nThe numbers you entered into the list will be displayed.\n";
	cout << "\nFollowing are the numbers entered: " << endl;
 
	list.print();
	cout << endl;
}
 
void searchList(double z)
{	
	cout << "Enter number to find in the list" << endl;
	cin >> z;
	list.isMember(z);
}
 
void deleteNode(double z)
{
	cout << "Enter number to delete from the list" << endl;
	cin >> z;
	list.deleteNode(z);
}

#include <iostream>
using namespace std;
 
// declare class ListNode
class ListNode
{
public:
    ListNode(double v, ListNode *p)
    {
        value = v; next = p;
    }
private:    
    double value;
    ListNode *next;
    friend class LinkedList; // LinkedList has friend status	
};
 
// declare class LinkedList
class LinkedList
{
public:
    void add(double x);
    bool isMember(double x);
	void deleteNode(double x);
    LinkedList( ) { head = NULL;}    
    void print();        
private:
    ListNode * head;
    static void rPrint(ListNode *pList);
};
 
//   define member print.            
void LinkedList::print()
{
    ListNode *p = head; // Use to walk through list
    while (p != NULL)
    {
		cout << p->value << " ";
        p = p->next;
    }
}
 
// define member add
void LinkedList::add(double x)
{
	// do not accept sentinel as data to be added to list
	// if sentinel is passed to function member - does not add to list
	// and escapes loop in listPrint.cpp
	if (x != -1)
	{
		head = new ListNode(x, head);
 
	}
	else
		return;
}
 
 
 
 
// define membber isMember
bool LinkedList::isMember(double x)
{
	int position = 0;
	ListNode *p = head; // Use p to walk through list
    while (p)
    {
        if (p->value == x) 
		{
			cout << "Value was found in the list in position " << position << ".\n\n";
			return true;
		}
        else
            p = p->next;
			position ++;
    }
    // List is exhausted without finding x
    return false;    
}
 
void LinkedList::deleteNode(double z)
{
	ListNode *nodePtr, *previousNodePtr;
 
	// If the list is empty, do nothing
	if (!head)
		return;
	// Determine if the first node is the one to delete
	if (head->value == z)
	{
		nodePtr = head;
		head = head->next;
		delete nodePtr;
	}
 
	else
 
	{
		//Initialize nodePtr to head of list
		nodePtr = head;
 
		//skip all nodes whose value member is not equal to z
		while (nodePtr != NULL && nodePtr->value != z)
		{
			previousNodePtr = nodePtr;
			nodePtr = nodePtr->next;
		}
 
		//link the previous node to the node after nodePtr, then delete nodePtr
		if (nodePtr)
		{
			previousNodePtr->next = nodePtr->next;
			delete nodePtr;
		}
	}
}

// define member add
void LinkedList::add(double x)
{
	// do not accept sentinel as data to be added to list
	// if sentinel is passed to function member - does not add to list
	// and escapes loop in listPrint.cpp
	if (x != -1)
	{
		if (head == NULL)
		{
			head = new ListNode(x, head);
		}
		else
		{
			ListNode *nodePtr = head;
			while (nodePtr->next != NULL)
			{
				nodePtr = nodePtr->next;
			}
			nodePtr->next = new ListNode(x, head);
		}
	}
	else
		return;
}