[BOJ 11839] Beautiful row

View as PDF

Submit solution

Points: 3
Time limit: 3.0s
Memory limit: 256M

Problem types
Allowed languages
Assembly, Awk, C, C++, Java, Pascal, Perl, Python, Sed, Text

Ali-Amir wrote N numbers in a row. A row is called beautiful if any two of the neighbour numbers in the row have got the same amount of ones in binary or ternary notations.</p>

Ali-Amir wants to count the number of ways the all given numbers can be written in a beautiful row.

입력 형식

The first line of input file contains integer N (2 ≤ N ≤ 20). The next line contains N non-negative integers not exceeding 109 each.

출력 형식

Output the number of ways the all given numbers can be placed in a beautiful row.

예제 입력

3
5 1 6

예제 출력

2

힌트

In the sample 5 = 123 and 1 = 13, 5 = 1012 and 6 = 1102, thus rows 1 5 6 and 6 5 1 are beautiful.


Comments

There are no comments at the moment.