import static java.lang.System.*;
import java.util.Arrays;
public class MergeSort{
private static int passCount;
public static void mergeSort(int[] list)
{
passCount=0;
mergeSort(list, 0, list.length);
}
private static void mergeSort(int[] list, int front, int back)
{
int mid = (front+back)/2;
if(mid==front) return;
mergeSort(list, front, mid);
mergeSort(list, mid, back);
merge(list, front, back);
}
private static void merge(int[] list, int front, int back)
{
int dif = back-front;
int[] temp = new int[dif];
int beg = front, mid = (front+back)/2;
int saveMid = mid;
int spot = 0;
while(beg < saveMid && mid < back) {
if(list[beg] < list[mid]) {
temp[spot++] = list[beg++];
} else {
temp[spot++] = list[mid++];
}
}
while(beg < saveMid)
temp[spot++] = list[beg++];
while(mid < back)
temp[spot++] = list[mid++];
for(int i = 0; i < back-front; i++) {
list[front+i] = temp[i];
}
System.out.println("pass " + passCount++ + " " + Arrays.toString(list) + "\n");
}
public static void main(String args[])
{
mergeSort(new Comparable[]{ 9, 5, 3, 2 });
System.out.println("\n");
mergeSort(new Comparable[]{ 19, 52, 3, 2, 7, 21 });
System.out.println("\n");
mergeSort(new Comparable[]{ 68, 66, 11, 2, 42, 31});
System.out.println("\n");
}
}