Strictly by the text of the NFHS rule, and it's cause/effect language, I have to conclude that A1's dribble has not ended. So if the ball is still bouncing when A1 gets to it, he could continue the dribble. If he controlled the ball with both hands, or it came to rest in one hand, then the dribble has ended.
Stepping back just a bit, I'd have to say that during an interrupted dribble an opponent touching the ball does not end the dribble. Assuming that the dribbler is able to retrieve the ball, whether the dribble ends depends on what he does next.
Under NCAA, the opponent batting the ball ends the dribble. So even continuing the dribble would ... be an illegal dribble? That doesn't quite add up.
