How do I loop through a string with an array of strings to find matches?

Question

I am trying to loop through a title string with an array of strings and see which ones from the array match.

My code works fine but I am not sure if it is the most efficient way to do this.

The important thing is that the strings in the array do not have to match a phrase in the title exactly. They can be in any order as long as every word is in the title. Any help would be great.

EX.title = "Apple Iphone 4 Verizon"
   array = ["iphone apple, verizon iphone", "iphone 3g", "iphone 4", "cool iphone"]

I need it to return ["iphone apple", "verizon iphone", "iphone 4"] . The words in the strings "verizon iphone" and "iphone apple" are in the title, the order does not matter

results = [] 

#Loop through all the pids to see if they are found in the title
all_pids = ["iphone 3gs", "iphone white 4", "iphone verizon", "black iphone", "at&t      iphone"]
title = "Apple Iphone 4 White Verizon"
all_pids.each do |pid|
    match = []
    split_id = pid.downcase.split(' ')
    split_id.each do |name|

      in_title = title.downcase.include?(name) 
      if in_title == true
        match << name
      end
    end

    final = match.join(" ")

    if final.strip == pid.strip
      results << pid
    end

end

print results

When I run this it prints what I need ["iphone white 4", "iphone verizon"]

Answer 1

It looks to me that you want to find the strings that are composed of strings that strictly intersect the strings in the title.

Array#- performs set difference operations. [2] - [1,2,3] = [] and [1,2,3] - [2] = [1,3]

title = "Apple Iphone 4 White Verizon"
all_pids = ["iphone 3gs", "iphone white 4", "iphone verizon", "black iphone", "at&t      iphone"]
set_of_strings_in_title = title.downcase.split
all_pids.find_all do |pid|
  set_of_strings_not_in_title = pid.downcase.split - set_of_strings_in_title 
  set_of_strings_not_in_title.empty?
end

EDIT: Changed #find to #find_all to return all matches, not just the first.

Answer 2

You could do something like the following:

>> require 'set'
=> true
>> title = "Apple Iphone 4 Verizon"
=> "Apple Iphone 4 Verizon"
>> all_pids = ["iphone apple", "verizon iphone", "iphone 3g", "iphone 4", "cool iphone"]
=> ["iphone apple", "verizon iphone", "iphone 3g", "iphone 4", "cool iphone"]
>> title_set = Set.new(title.downcase.split)
=> #<Set: {"apple", "iphone", "4", "verizon"}>
>> all_pids.select { |pid| Set.new(pid.downcase.split).subset? title_set }
=> ["iphone apple", "verizon iphone", "iphone 4"]

You can do something very similar with array differences, but sets might be faster since they are implemented as hashes.