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

//Structure for linked list
struct node
{
    int data;
    node *next;
};

void display_list(node*, int);

int main()
{
    //Create linked list
    node * head = new node;
    node * ptr = head;
    node * temp = nullptr;

    //DATA
    int numberOfNodes = 0;
    int userNumber = 0;
    int index = 0;

    //Prompt user for proper input
    while (numberOfNodes < 1)
    {
        cout << "Enter the number of initial nodes (must be at least 1): ";
        cin >> numberOfNodes;
    }

    //Fill list
    for (int i = 0; i < numberOfNodes; i++)
    {
        //Prompt for data
        cout << "Enter a number: ";
        cin >> userNumber;
        ptr->data = userNumber;

        //Connect tail to nullptr
        if (i == numberOfNodes - 1)
        {
            ptr->next = nullptr;
        }
        //Creat a new node and pointer
        else
        {
            ptr->next = new node;
            ptr = ptr->next;
        }
    }

    //Set pointer to beginning of list
    ptr = head;

    //Output data in list
    display_list(ptr, numberOfNodes);

    //Insert into linked list
    do
    {
        cout << "Enter the index to insert a node: ";
        cin >> index;
        if (index >= numberOfNodes)
        {
            cout << "Invalid index. Please enter an index below the number of nodes." << endl;
        }
    } while (index >= numberOfNodes);
    cout << "Enter a number for a new node to insert to the linked list: ";
    cin >> userNumber;

    //Set pointer to beginning of list
    ptr = head;

    //Have pointer point to index
    for (int i = 0; i < index - 1; i++)
    {
        ptr = ptr->next;
        if (ptr->next == nullptr)
        {
            temp = nullptr;
        }
        else
        {
            temp = ptr->next;
        }
    }

    //Insert node
    ptr->next = new node;
    ptr->data = userNumber;
    ptr = temp;
    ptr = head;


    display_list(ptr, numberOfNodes);

    return 0;
}

void display_list(node* ptr, int numberOfNodes)
{
    //Output data in list
    for (int i = 0; i < numberOfNodes; i++)
    {
        cout << (ptr->data) << endl;
        ptr = ptr->next;
    }
}