Careercup - Microsoft面试题 - 5204967652589568

2014-05-11 23:57

题目链接

原题：

9 identical balls. one ball is heavy. find the heavy ball with only 2 measurements ........ dead easy.

题目：9个看起来一样的球，其中有一个偏重。给定一个不能给出具体重量，但可以比较轻重的天平，称2次找出那个重球。

解法：9个球三等分，称一次找出包含重球的那三个。3个球三等分，称一次找出重球。

代码：

// http://www.careercup.com/question?id=5204967652589568
Answer:
    Split the 9 balls into three groups of 3 balls.
    Choose two groups and weigh them on the balance:
        If balanced, the heavy ball is in the other group.
        If imbalanced, the heavy ball is in the heavier group.
    Find the group with the heavy ball, pick two balls from the three and weigh them:
        If balanced, the heavy ball is the other one.
        If imbalanced, the heavy ball is the heavier one.