Merge Sort using Java

Hi All,

Here I write a program for Merge Sort using java

Merge sort or merge sort is a simple but efficient sort algorithm that splits the list into two sub lists, sorts each one, then combines them into a single sorted list. It has good worst-case performance and requires only sequential access, making it ideal for sequential data structures like linked lists.

package Sorting;

import java.util.Scanner;

/* sort method */
public class MergeSort1 {

    static void MergeMethod(int a[], int b) {
        int sub[] = new int[25];
        int i, j, k, lev1, lev2, lev3, u2, size;
        size = 1;
        while (size < b) { // check the array size
            lev1 = 0;
            k = 0;
            while ((lev1 + size) < b) {
                lev2 = lev1 + size;
                lev3 = lev2 - 1;
                u2 = ((lev2 + size - 1) < b) ? (lev2 + size - 1) : (b - 1);
                for (i = lev1, j = lev2; i <= lev3 && j <= u2; k++) {
                    if (a[i] <= a[j]) {
                        sub[k] = a[i++];
                    } else {
                        sub[k] = a[j++];
                    }
                }
                for (; i <= lev3; k++) {
                    sub[k] = a[i++];
                }

                for (; j <= u2; k++) {
                    sub[k] = a[j++];
                }
                lev1 = u2 + 1;
            }
            for (i = lev1; k < b; i++) {
                sub[k++] = a[i];
            }
            for (i = 0; i < b; i++) {
                a[i] = sub[i];
            }
            size *= 2;
        }
    }

    public static void main(String args[]) {
        int i, n;
       /* Getting value  from user */
        Scanner in = new Scanner(System.in);
        System.out.print("Please Enter how many numbers to be sorted : \t");
        n=new Scanner(System.in).nextInt();  
        System.out.println("\nEnter the numbers\n");
        int x[] = new int[n];
        for (i = 0; i < n; i++) {
            x[i] = in.nextInt();
        }
        MergeMethod(x, n);

        /* print out put of array*/
        System.out.println("\nSorted Elements are :");
        for (i = 0; i < n; i++) {
            System.out.print(x[i] + "  ");
        }
    }
}

OUTPUT:

~~~~~~~~

Please Enter how many numbers to be sorted :     8

Enter the numbers

5
60
2
1
95
25
35
3

Sorted Elements are :
1  2  3  5  25  35  60  95