private void closestPairSplit(Point[] pY, Point[] aux, int lo, int mid, int hi) {
		for (int i = lo; i <= hi; i++) {
			aux[i] = pY[i];
		}
		int ii = lo, jj = mid + 1;
		for (int i = lo; i <= hi; i++) {
			if (ii > mid) pY[i] = aux[jj++];
			else if (jj > hi) pY[i] = aux[ii++];
			else {
				if (aux[ii].x < aux[mid].x)
					pY[i] = aux[ii++];
				else 
					pY[i] = aux[jj++];
			}
		}
	}