import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.ListIterator;
public class Numbers
{
    public ArrayList<Double> numbers;

    /**
     * Constructor
     */
    public Numbers()
    {
        numbers = new ArrayList<Double>();
    }

    /**
     * Direct
     */
    public void displayNumbers()
    {
        for(Double x : numbers)
        {
            System.out.println(x);
        }
    }

    public void displayNumberss()
    {
        for(int i=0; i < numbers.size(); i++){
            System.out.println("<tr>");
        }
    }

    /**
     * Direct
     */
    public void addNumber(double num)
    {
        numbers.add(num);
    }

    /**
     * Direct
     */
    public void addNumber(double num, int position)
    {
        if(position >= 0 && position <= numbers.size())
            numbers.add(position,num);
        else
        {
            System.out.println("Error.");
        }
    }

    /**
     * Direct
     */
    public void displayLargest()
    {
        double max = numbers.get(0);
        for(int i = 1;i < numbers.size(); i++)
            if(numbers.get(i) > max)
                {
                    max = numbers.get(i);
                }
        System.out.println(max);
    }

    public void displaySmallest()
    {
        double min = numbers.get(0);
        for(int i = 1;i < numbers.size(); i++)
        {
            if(numbers.get(i) < min)
                {
                    min = numbers.get(i);
                }
             System.out.println(min);
        }
    }

    public void displayCategories()
    {
        System.out.println("Negative numbers");
        for(int i = 1;i < numbers.size(); i++)
        {
            if(numbers.get(i) < 0)
            {
                System.out.println(numbers.get(i));
            }
        }
        System.out.println("Positive numbers");
        for(int i = 1;i < numbers.size(); i++)
        {
            if(numbers.get(i) >= 0)
            {
                System.out.println(numbers.get(i));
            }
        }
    }

    public void displaySum()
    {
        double sum = 0;
        for(int i = 0;i < numbers.size(); i++)
        {
            sum = sum + numbers.get(i);
        }
        System.out.println("The sum of all the numbers is " + sum);
    }

    public void displayPositiveCategories()
    {
        double sumPositive = 0;
        double sumNegative = 0;
        for(int i = 0;i < numbers.size(); i++)
        {
            if(numbers.get(i) >= 0)
            {
                sumPositive = sumPositive + numbers.get(i);
            }
        }
        for(int i = 0;i < numbers.size(); i++)
        {
            if(numbers.get(i) < 0)
            {
                sumNegative = sumNegative + numbers.get(i);
            }
        }
        System.out.println("Positive sum is " + sumPositive);
        System.out.println("Negative sum is " + sumNegative);
    }

    public void displayPositiveAvg()
    {
        double mean = 0;
        for(int i = 0;i < numbers.size(); i++)
        {
            mean = mean + numbers.get(i);
        }
        mean = mean / numbers.size();
        System.out.println("The mean is " + mean);
    }

    public void displayNumbersIterator()
    {
        Iterator it = numbers.iterator();
        while(it.hasNext())
        {
            System.out.println(it.next());
        }
    }

    public void addNumberIterator(double num)
    {
        ListIterator it = numbers.listIterator();
        it.add(num);
    }

    public void displayCategoriesIterator()
    {
        Iterator it = numbers.iterator();
        System.out.println("Negative numbers");
        for(int i = 0;i < numbers.size(); i++)
        {
            if(numbers.get(i) < 0 && it.hasNext())
            {
                System.out.println(it.next());
            }
        }
        System.out.println("Positive numbers");
        for(int i = 0;i < numbers.size(); i++)
        {
            if(numbers.get(i) >= 0 && it.hasNext())
            {
                System.out.println(it.next());
            }
        }
    }



}