package com.undiksha.mergesort;

import java.util.Scanner;

public class Belajar {


    void merge(int arr[], int l, int m, int r)
    {
        // Find sizes of two subarrays to be merged
        int n1 = m - l + 1;
        int n2 = r - m;

        /* Create temp arrays */
        int L[] = new int [n1];
        int R[] = new int [n2];

        /*Copy data to temp arrays*/
        for (int i=0; i<n1; ++i)
            L[i] = arr[l + i];
        for (int j=0; j<n2; ++j)
            R[j] = arr[m + 1+ j];


        /* Merge the temp arrays */

        // Initial indexes of first and second subarrays
        int i = 0, j = 0;

        // Initial index of merged subarry array
        int k = l;
        while (i < n1 && j < n2)
        {
            if (L[i] <= R[j])
            {
                arr[k] = L[i];
                i++;
            }
            else
            {
                arr[k] = R[j];
                j++;
            }
            k++;
        }

        /* Copy remaining elements of L[] if any */
        while (i < n1)
        {
            arr[k] = L[i];
            i++;
            k++;
        }

        /* Copy remaining elements of R[] if any */
        while (j < n2)
        {
            arr[k] = R[j];
            j++;
            k++;
        }
    }

    // Main function that sorts arr[l..r] using
    // merge()
    void sort(int arr[], int l, int r)
    {
        if (l < r)
        {
            // Find the middle point
            int m = (l+r)/2;

            // Sort first and second halves
            sort(arr, l, m);
            sort(arr , m+1, r);

            // Merge the sorted halves
            merge(arr, l, m, r);
        }
    }




    public static void main(String[] args)
    {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Masukan Panjang Array : ");
        int panjangArray = scanner.nextInt();

        int[] array     = new int[panjangArray];

        //memasukan nilai ke semua element array
        System.out.println("Masukan nilai di setiap element array");
        for(int i=0;i<panjangArray;i++)
        {
            array[i] = scanner.nextInt();
        }

        //menampilkan semua element array yang barus aja dimasukan
        System.out.println("Array yang baru saja dimasukan");
        for(int i=0;i<panjangArray;i++)
        {
            System.out.print(array[i]+" ");
        }
        Belajar sort = new Belajar();
        sort.sort(array, 0, panjangArray-1);

        System.out.println("\nArray yang sudah terurut");
        for(int i=0;i<panjangArray;i++)
        {
            System.out.print(array[i]+" ");
        }




    }
}