Merge Sort

Mergesort.

To develop a faster sorting method, we use a divide-and-conquer approach to algorithm design that every programmer needs to understand. This nomenclature refers to the idea that one way to solve a problem is to divide it into independent parts, conquer them independently, and then use the solutions for the parts to develop a solution for the full problem. To sort an array with this strategy, we divide it into two halves, sort the two halves independently, and then merge the results to sort the full array. This method is known as mergesort.

This is a program  :
import jeliot.io.*;

public class mergeSort{
  public static void main(String a[]){
    int i;
    int array[] = {12,9,4,7,15,1,3,10};
    System.out.println("\n\n       RoseIndia\n\n");
    System.out.println("       Merge Sort\n\n");
    System.out.println("Values Before the sort:\n");
    for(i = 0; i < array.length; i++)
      System.out.print( array[i]+"  ");
    System.out.println();
    mergeSort_srt(array,0, array.length-1);
    System.out.print("Values after the sort:\n");
    for(i = 0; i <array.length; i++)
      System.out.print(array[i]+"  ");
    System.out.println();
    System.out.println("PAUSE");
  }
  public static void mergeSort_srt(int array[],int lo, int n){
    int low = lo;
    int high = n;
    if (low >= high) {
      return;
    }

    int middle = (low + high) / 2;
    mergeSort_srt(array, low, middle);
        mergeSort_srt(array, middle + 1, high);
    int end_low = middle;
    int start_high = middle + 1;
    while ((lo <= end_low) && (start_high <= high)) {
      if (array[low] < array[start_high]) {
        low++;
            } else {
        int Temp = array[start_high];
        for (int k = start_high- 1; k >= low; k--) {
          array[k+1] = array[k];
        }
                array[low] = Temp;
                low++;
                end_low++;
                start_high++;
            }
        }
    }
}