CODEWITHSUNDEEP
ruby
Sarah Ryan
Sarah Ryan

Reputation: 51

ruby comparing two arrays of what they have in common

I want to be able to compare two arrays of what they have in common and not show any duplicates.

array1 = ['1. walking to the park to find some ice cream']
array2 = ['2. walking to the park to find ice cream and find more ice cream']

sample output:

walking to the park find ice cream

Upvotes: 0

Views: 81

Answers (2)

jstim
jstim

Reputation: 2432

  1. Start with two strings
  2. Split them both on spaces
  3. Do an array intersection on them
a = '1. walking to the park to find some ice cream'
b = '2. walking to the park to find ice cream and find more ice cream'

a1 = a.split(" ")
b1 = b.split(" ")

common = a1 & b1
#=> ["walking", "to", "the", "park", "find", "ice", "cream"]

Regex will be slower. Here's a quick comparison between array union and using Regexp:

require 'benchmark'

def arr_only(a,b)
  a1 = a.split(" ")
  b1 = b.split(" ")
  a1 & b1
end

def w_regex(a,b)
  match = Regexp.union(a.split(" "))
  b.scan(match).uniq
end

n = 100_000
Benchmark.bm do |x|
  x.report("arr:") { n.times {|i| arr_only(a, b) } }
  x.report("regex:"){ n.times {|i| w_regex(a, b) } }
end

#                   user     system      total        real
# arr:          1.030000   0.000000   1.030000 (  1.031033)
# regex:        4.970000   0.010000   4.980000 (  4.993263)

Upvotes: 7

Arup Rakshit
Arup Rakshit

Reputation: 118271

I would do as :

a = '1. walking to the park to find some ice cream'
b = '2. walking to the park to find ice cream and find more ice cream'

match = Regexp.union(a.split(" "))
b.scan(match).uniq.join(" ")
# => "walking to the park find ice cream"

Upvotes: 1

Related Questions