package Assignment4;

import java.util.Arrays;

public class TestMergeSort
{


    public static void main (String args[])
    {
        String[] names = {"Lisa", "Adam", "John", "Vicky", "George", "Beth", "Kate", "Aaron", "Jinny"};
        mergeSort(names);
        for (String s :names)
        {
            System.out.println(s);
        }
    }
    /**
     * This function recursively splits the original array into halves until each node is 1 entry.
     * @param names a array of type string
     */
    public static void mergeSort (String[] names)
    {
        if (names.length >= 2)//Breaks array into pairs
        {
            String[] a = new String[names.length/2]; //Makes an array half the size of the original
            String[] b = new String[names.length - names.length/2];//Makes an array for the rest of the size of the original
            for (int i=0; i<a.length;i++)
            {
                a[i]=names[i];//Puts half the original array into a temp array
            }
            for (int i=0; i<b.length; i++)
            {
                b[i] = names[i + names.length /2];//Puts the other half of the array into a temp array
            }
            mergeSort(a);
            mergeSort(b);
            merge(names, a, b);
        }
    }
    /**
     * This function takes the nodes then merges them in order
     * @param names An array of type string
     * @param a An array of type string
     * @param b An array of type string
     */
    public static void merge (String[] names, String[] a, String[] b)
    {
        int count1=0;
        int count2=0;
        System.out.println("Pre loop names is: " + Arrays.toString(names));

        for (int i=0; i<names.length; i++)
        {

            if (count2>= b.length || count1<a.length && a[count1].compareToIgnoreCase(b[count2]) < 0)//ensures array does not go out of bounds, and sorts array
            {
                names[i]=a[count1];
                count1++;
            }
            else
            {
                names[i]=b[count2];
                count2++;
            }
        }
    }