乌鸦喝水的练习。计算乌鸦要丢多少石头才能喝到水呢？如果假设乌鸦喝到的是毒药会怎样？如果石头是炸药怎样？适合java面向对象的初学者-Crow drinking practice. Calculate the number of crows to throw stones in order to drink water? If the assumption is that crow drink poison what would happen? If the stone is what dynam