package set2;

import java.util.*; import java.util.concurrent.ForkJoinPool; import java.util.concurrent.RecursiveAction;

public class Application {

public static void main(String[] args) {
    // TODO Auto-generated method stub
    int[] array = {4,5,1,8,9,2};
    System.out.println(Arrays.toString(array));
    ForkJoinPool fjk= new ForkJoinPool();

    fjk.invoke(new bubblesorttask(array));


    System.out.println("sorted array: " + Arrays.toString(array));
}

}
class bubblesorttask extends RecursiveAction{

private int[] a;
private int low;
private int high;

private static final int THRESHOLD = 1000;

public bubblesorttask(int[] array) {
    this(array,0,array.length-1);

}

public bubblesorttask(int[] array, int start, int end) {
    // TODO Auto-generated constructor stub
    this.a=array;
    this.high=end;
    this.low=start;

}

@Override
protected void compute() {
    // TODO Auto-generated method stub
    if (high-low <= THRESHOLD) {
        bubblesort();
    }
    else
    {
        int mid= low  + (high-low)/2;
        bubblesorttask lefttask= new bubblesorttask(a,low,mid);
        bubblesorttask righttask=new bubblesorttask(a, mid+1, high);

        invokeAll(lefttask,righttask);

        merge(lefttask.a,righttask.a);

    }


}

private void merge(int[] leftarray, int[] rightarray) {
    // TODO Auto-generated method stub
    int i=0,j=0,k=low;
    while (i<leftarray.length && j< rightarray.length) {
        if(leftarray[i]<= rightarray[i]) {
            a[k]= leftarray[i];
            i++;
        }
        else
        {
            a[k]= rightarray[i];
            j++;
        }
        k++;
    }
    while (i<leftarray.length) {
        a[k]=leftarray[i];
        i++;
        k++;


    }
    while ( i<rightarray.length) {
        a[k]=rightarray[i];
        j++;
        k++;
    }
}

private void bubblesort() {
    // TODO Auto-generated method stub
    for (int i= low; i< high;i++) {
        for (int j=low;j<= high-i-1;j++) {
            if(a[j]>a[j+1]) {
                int temp=a[j];
                a[j]=a[j+1];
                a[j+1]=temp;

            }
        }
    }

}

}