CODEWITHSUNDEEP
ruby
user3576036
user3576036

Reputation: 1425

Comparing two arrays with each other

I am trying to solve some problems in ruby get a hold. I am trying compare two arrays with each other.

Array1 = [1,0,1,0,1,1]
Array2=  [0,0,1,0,1,0]

I am getting this input from the user. Then I am comparing the votes. If both persons have upvoted 1 at same index, I am trying increment an empty array by 1. 

def count_votes
  bob_votes = gets.chomp
  alice_votes = gets.chomp
  bvotes = bob_votes.split('')
  avotes = alice_votes.split('')
  common_upvotes = []
  bvotes.each.with_index(0) do |el, i|
    if bvotes[i] == 1
    common_upvotes << 1
  end
end

I actually want to compare avotes with bvotes and then increment empty array by 1. I need a little help

Upvotes: 0

Views: 147

Answers (3)

Aleksei Matiushkin
Aleksei Matiushkin

Reputation: 121000

You can use Array#zip and Enumerable#count:

array1 = [1,0,1,0,1,1]
array2=  [0,0,1,0,1,0]
array1.zip(array2)
#⇒ [[1, 0], [0, 0], [1, 1], [0, 0], [1, 1], [1, 0]]
array1.zip(array2).count { |v1, v2| v1 == v2 && v1 == 1 }
#⇒ 2

or (credits to @engineersmnky):

array1.zip(array2).count { |v1, v2| v1 & v2 == 1 }

or even better (credits to @Stefan):

array1.zip(array2).count { |values| values.all?(1) }

or

array1.
  zip(array2).
  reject { |v1, v2| v1 == 0 || v2 == 0 }.
  count
#⇒ 2

Sidenote: capitalized Array1 declares a constant. To declare a variable, use array1 instead.

Upvotes: 4

Cary Swoveland
Cary Swoveland

Reputation: 110675

The number of indices i for which Array1[i] == 1 && Array2[i] == 1 is

Array1.each_index.count { |i| Array1[i] == 1 && Array2[i] == 1  }
  #=> 2

The array of indices i for which Array1[i] == 1 && Array2[i] == 1 is

Array1.each_index.select { |i| Array1[i] == 1 && Array2[i] == 1  }
  #=> [2, 4]

The number of indices i for which Array1[i] == Array2[i] is

Array1.each_index.count { |i| Array1[i] == Array2[i] }
  #=> 4

Upvotes: 1

iGian
iGian

Reputation: 11193

If you want to build a new array tracking the index where there is a match of upvotes:

a1 = [1,0,1,0,1,1]
a2=  [0,0,1,0,1,0]
p [a1, a2].transpose.map {|x| x.reduce(:&)}

#=> [0, 0, 1, 0, 1, 0]

For just counting, this is another way:

a1 = [1,0,1,0,1,1]
a2=  [0,0,1,0,1,0]

votes = 0
a1.each_with_index do |a1, idx|
  votes +=1 if (a1 + a2[idx]) == 2
end

p votes #=> 2

In one line:

a1.each_with_index { |a1, idx| votes += 1 if (a1 + a2[idx]) == 2 }

Upvotes: 0

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