When the switch is at A, its an RL ckt, and when its at B you have a RLC ckt. Calculate the waveforms for each of those. For the various switch points in time, find where (in time) it is in those waveforms and scale the levels accordingly. for example, the second time the switch switches to B, you know how much current is in the inductor and how much voltage is in the cap, the ratio of those tells you at what point in time of the waveform of that RLC ckt they are. And of course, don't forget the cap holds its charge when the switch is at A.
EDIT: Practically speaking, flipping that switch will waste a little energy, too. But I'm almost sure you are suppose to ignore that here.