get_pairs.rb

# You have an array of ints. Create function which groups numbers by sum of pairs
# (for example: sum = 5). Each element of array has to be used only once.
#     function getPairs(arr, sum) {
#       // ...
#     }
# ---
# test data:
#     input: [22, 3, 5, 0, 2, 2]
# resutls: [[3, 2], [5, 0]]
# input: [-5, 33, 2, 2, 3, 5, 0, 10, 3]
# resutls: [[-5, 10], [2, 3], [2, 3], [5, 0]]
# input: [5, 5, 5, 0, 0, 0, 5]
# resutls: [[5, 0], [5, 0], [5, 0]]
# sum=6
# input: [3, 3, 6, 0]
# resutls: [[3, 3], [6, 0]]
# # Language: JavaScript or Ruby (of your choice)

param = 5
input = [-5, 33, 2, 2, 3, 5, 0, 10, 3]

def get_pairs(arr, sum)
  result = []
  comb = arr.combination(2).to_a
  comb.each do |pair|
    if pair.sum == sum && arr.any?
      if arr.find_index(pair[0]) && arr.find_index(pair[1])
        arr.delete_at(arr.find_index(pair[0])) && arr.delete_at(arr.index(pair[1]))
        result << pair
      end
    end
  end
  result
end

p get_pairs(input, param)