微软的一道题目，有12个外表一模一样的小球，其中有一个的质量和其他11个球不一样（11个球的质量完全相同），而且该球不知道是轻点还是重点。现在给你一个天平（无砝码），只有3次测量机会，请你找出该球。球号从a到l(小写)-Microsoft' s one topic, there are 12 look exactly the same ball, one of which the quality and not the same as the other 11 balls (11 balls of the same quality), and that the ball does not know or focus of light spots. Now to give you a balance (no weight), only three measurements chance, would you please identify the ball. Ball number from a to l (lowercase)