Minimize nested loops - ruby-on-rails

Question

I have the following code with nested loops. How can I minimize the loop?
users result is like:
users = [[35, 61, 62, 63, 64, 65, 66, 67, 68, 69, nil, 70, 71, 72, 73,
74, 75, 78, 79, 92, 94, 95, 154, 164, 292, 293, 294, 295, 314],
[],
[35],
[],
[35, 79, 88],
[],
[],
[36, 35, 56, 78, 87, 95, 65],
[63, 72, 78, 80, 81, 82, 84, 87, 90, 93, nil, 96, 111, 157, 159, 160, 271,
272, 66, 295, 296, 297, 298, 299, 300, 301, 305, 307, 308, 71, 315],
[],
[79, 83, 85, 86, 89, 91, 161, 162, 163, 67, 294, 302, 303, 304, 306,
309, 310, 311, 312, 313],
[],
[314],
[314],
[]
]
That's why I need to loop the object in each elements.
And array value is:
array = [309, 310, 305, 304, 90, 162, 78, 297, 296, 272, 271, 84, 91, 308,
299, 79, 87, 298, 301, 163, 81, 72, 83, 111, 86, 313, 164, 300, 159,
315, 160, 307, 82, 69, 312, 89
]
Thanks!
0.upto(users.count).each do |i|
users[i].each do |user_id|
if array.include?(user_id)
puts user_id
end
end
end

Answer 1

From my understanding, you want to get the common elements from users and array.
At first make the users array flatten to make it a single array. Then make it a uniq so that one id doesn't repeat again. compact will remove the nil values. After that make a & operation with array. And you got your result.
result = users.flatten.uniq.compact & array
Now if you want to print the result
puts result

Answer 2

If each sub array of users has no repeated elements, then the following should work
users.each { |user| puts array & user }