问散列用于将每个值相加。

EN

1.upto(input.size).
  flat_map do |i|
    input.to_a.combination(i).select do |arrs|
      arrs.map(&:last).reduce(:+) == 100
    end
  end.
  map(&:to_h)
#⇒ [{"Hulk"=>25, "IronMan"=>75},
#   {"Groot"=>51, "Black Panther"=>49},
#   {"Captain America"=>50, "Thor"=>50}]

input = { 
  "Hulk" => 25,
  "IronMan" => 75,
  "Groot" => 51,
  "Captain America" => 50,
  "Spider Man" => 40,
  "Thor" => 50,
  "Black Panther" => 49
}

# Create inverse lookup map
inverse_input = input.each.with_object(Hash.new([])){ |(k, v), h| h[v] += [k] }
#=> {25=>["Hulk"], 75=>["IronMan"], 51=>["Groot"], 50=>["Captain America", "Thor"], 40=>["Spider Man"], 49=>["Black Panther"]}

input.flat_map do |hero, power| 
  # Get heroes with needed power only
  other_heroes = inverse_input[100 - power]
  # Remove current hero from the list
  other_but_this = other_heroes.reject{ |name| name == hero }
  # Map over remaining heroes 
  # and sort them for later `uniq` filtering
  other_but_this.map { |h| [hero, h].sort }
end.compact.uniq
# compact will remove nils
# uniq will remove duplicates
#=> [["Hulk", "IronMan"], ["Black Panther", "Groot"], ["Captain America", "Thor"]]

input.to_a.
      permutation(2).
      select{|(n1,v1), (n2, v2)| n1 != n2 && v1 + v2 == 100 }.
      map{ |l,r| [l.first, r.first].sort }.
      uniq
#=> [["Hulk", "IronMan"], ["Black Panther", "Groot"], ["Captain America", "Thor"]]

all_options = input.map { |a| input.without(a).map { |b| [a, b] } }.flatten(1).sort.uniq

valid_options = all_options.select { |r| r.sum(&:second) == 100 }

input.combination(2).select { |r| r.sum(&:second) == 100 }.map(&:to_h)