用面向对象思想完成的9个重要外观的球，其中一个重量不一样，只用一个天平，将球用最少次数挑选出来。-object-oriented thinking completed nine major appearance of the ball, a weight not the same, only a balance, comes with the least number selected.

jmousetrap讲的是：一群老鼠在一个世界里，同时旁边放了很多乒乓球，一个老鼠把球抛向空中砸到另一只老鼠，另一只老鼠则也把球跑向空中。最终会产生一个平衡状态-jmousetrap say is this: a group of rats in a world, next to put a lot of table tennis at the same time, a mouse ball into the air fall on the other mice, another mouse w