From: Johan Holmberg <holmberg@...>
Date: 2002-09-19T17:20:03+09:00
Subject: Re: How to Efficiently Calculate the Pattern of Zeros and Ones?

William Djaja Tjokroaminata <billtj@z.glue.umd.edu> writes:
> 
> For example, with m = 2:
> 
>     [1 0 0 1 0 0 5 1]   --> 2
>     [0 0 1 0 0 1 0 2]   --> 1
>     [1 0 1 0 1 0 1 0]   --> 0
>     [1 0 0 0 0 0 1 0]   --> 2
> 

I don't know if the following is efficient in terms of CPU-cylces
but it is at least rather short and easy to read (once you know
the cool enum-package).

/Johan Holmberg

#----------------------------------------------------------------------
require "enum/cluster"

lists = [
    [1, 0, 0, 1, 0, 0, 5, 1],
    [0, 0, 1, 0, 0, 1, 0, 2],
    [1, 0, 1, 0, 1, 0, 1, 0],
    [1, 0, 0, 0, 0, 0, 1, 0],
]

facit = [0, 0, 1, 0, 0]
m = 2

for list in lists
    count = 0
    list.each_with_neighbors(m, 0) do |part|
        count += 1 if part == facit
    end
    puts "# in #{list.inspect} = #{count}"
end
#----------------------------------------------------------------------