有十二个外形无区别的球,其中有一个球在质量上与其他的球不同,本文介绍三种仅用一架天平称三次将质量不同的球找出来的方法.本文所提供的方法巧妙地采用了编码方法,此方法对所给球和称量结果分别进行编码,然后利用特殊球的编码与称量结果的编码之间的关系找出问题球并判明轻重,同时给出了该方法的具体实施时的选码、称量规则以及推广到一般情况.一、问题的提出有十二个外形无区别的球,其中有一个因质量原因不合 There are twelve undifferentiated balls, one of which is different in mass from the others. This article presents three ways to find different quality balls with just one balance, three times. The method provided in this article is subtle Using a coding method, this method for the ball and weighing the results were coded, and then use the special ball coding and weighing results of the relationship between the code to identify the problem ball and determine the severity, given the method The specific implementation of the election code, weighing rules and generalize to the general situation .One, the problem raised there are twelve balls without distinction, one of them because of quality reasons