No.23 December 23,2009

geslon

Neighborhood Value Let us define “neighborhood value” as the sum of the products of every consecutive numeral pair with the number of digits between them. Example: The neighborhood value for 132 is 2 (1x2x1 + 2x3x0 = 2). There is a single digit between the consecutive numerals 1 and 2, hence 1x2x1. There is no digit between the consecutive numerals 2 and 3, hence 2x3x0. Their sum 2 is the neighborhood value. Likewise, the neighborhood value for 4253 is 2x3x1 + 3x4x2 + 4x5x1 = 50. Which number with distinct numerals has the largest neighborhood value? If there exists more than one such number, please enter the largest of these numbers as your answer.

geslon

这题不难，但是英文理解能力不够，对其字面含义吃不准。 是不是从0到9这10个数字可以各使用一遍？

jmouse

举例应该很明显了，就是数相邻的数字之间有几个，然后乘起来并求和。 4253 2-->3: 之间有一个数字5，所以2*3*1 3-->4: 之间有两个数字25，所以3*4*2 4-->5: 之间有一个数字2，所以4*5*1 总和是50 最终答案应该是包含0-9的。 目前我找到1526。

sjymb

有什么好方法么？

东邪

貌似不难，小心阴沟。

geslon

jmouse小心，答案可不是要求你说出那个Neighborhood Value，是要你提交那个十位数字。 虽然很简单，不过别交错了答案。 因为竞赛道德要求，不方便在竞赛期间过多讨论，大家就不要公开说出自己的答案了。

jmouse

确实是要小心阴沟。。。今年已经失误两回了。