题目网址: http://www.puzzleup.com/2014/
http://www.puzzleup.com/2014/puzzle/?246
答题时限: 8月28日7PM-比赛结束(约12月17日)
加分时限: 8月28日7PM-9月3日6:59PM
答对可得基本分100分。答案可上传5次,每改1次答案从基本分扣20分。
比赛期间内可随时上传答案,加分时限内答对第n天加(6-n)分
另依题目的难易有额外加分(如有80%的人这题答错,答对者加80分)
◆Neighboring Digits
What is the greatest number in which all the digits, except the first and the
last digit, are smaller than the geometric mean of its neighbors? (Neighbors
of a digit are the digits to the immediate left and right of that digit)
For this problem, the geometric mean of two numbers (including zero) is the
square root of the product of those two numbers.
试问符合以下条件的最大数为何:
此数的所有位数,除了首位及末位外,皆小于其邻居的几何平均。
(某位数的邻居即为其左邻及右邻的数位)
在此问题中,两数(包含零)的几何平均定义为此两数乘积的平方根。