TheAlgorithms-Ruby/data_structures/disjoint_sets/disjoint_sets.rb

require "./data_structures/disjoint_sets/node.rb"

class DisjointSets
    def make_set(d)
        Node.new(d)
    end

    def find_set(x)
        raise ArgumentError unless x.class <= Node
        x.parent=(find_set(x.parent)) unless x.parent == x
        x.parent
    end

    def union_set(x, y)
        px = find_set(x)
        py = find_set(y)
        return if px == py
        if px.rank > py.rank
            py.parent = px
        elsif py.rank > px.rank
            px.parent = py
        else
            px.parent = py
            py.rank += 1
        end
    end
end

ds = DisjointSets.new
one = ds.make_set(1)
two = ds.make_set(2)
three = ds.make_set(3)
ds.union_set(one, two)
puts ds.find_set(one) == ds.find_set(two) # should be true
ds.union_set(one, three)
puts ds.find_set(two) == ds.find_set(three) # should be true
puts one.rank + two.rank + three.rank == 1 # should be true