10134 - 牛式

下面是一个乘法竖式,如果用我们给定的那几个数字来取代*,可以使式子成立的话,我们就叫这个式子牛式。

  * * *

x * *

-------
  * * *
* * *
-------
* * * *

数字只能取代*,当然第一位不能为0。

写一个程序找出所有的牛式。

输入

Line 1: 数字的个数。

Line 2: N个用空格分开的数字(每个数字都∈{1,2,3,4,5,6,7,8,9}) 。

输出

共一行,一个数字。表示牛式的总数。下面是样例的那个牛式。

  2 2 2
x   2 2
 ------
  4 4 4
4 4 4
4 8 8 4

样例

输入

5
2 3 4 6 8

输出

1

提示

Prime Cryptarithm

The following cryptarithm is a multiplication problem that can be solved by substituting digits from a specified set of N digits into the positions marked with *. If the set of prime digits {2,3,5,7} is selected, the cryptarithm is called a PRIME CRYPTARITHM.

  * * *

x * *

-------
  * * *
* * *
-------
* * * *

Digits can appear only in places marked by `*'. Of course, leading zeroes are not allowed. Write a program that will find all solutions to the cryptarithm above for any subset of digits from the set {1,2,3,4,5,6,7,8,9}.

PROGRAM NAME: crypt1 INPUT FORMAT Line 1: N, the number of digits that will be used Line 2: N space separated digits with which to solve the cryptarithm

SAMPLE INPUT (file crypt1.in) 5 2 3 4 6 8

OUTPUT FORMAT A single line with the total number of unique solutions. Here is the solution for the sample input:

  2 2 2
x   2 2
 ------
  4 4 4
4 4 4
4 8 8 4

SAMPLE OUTPUT (file crypt1.out) 1

时间限制 1 秒
内存限制 128 MB
讨论 统计
上一题 下一题