Find pairs in array with difference of n

find_pairs.rb

number_list = [4, 3, 33, 237, 2, 95, 17, 6, 67, 9, 19, 54, 8, 18, 25, 31, 1, 101, 234, 236, 100, 63, 68, 69]
input = 2

def find_pairs(array)
    pairs = []
    array.each_with_index do |px1, i|
       for px2 in array[i+1..-1]
       potential_difference1 = px2 - px1
       potential_difference2 = px1 - px2
        input = 2
        if input == potential_difference1 || input == potential_difference2
            pairs.push([px1, px2])
        end
      end

   end
    return pairs.count
end
puts find_pairs(number_list)