require "map"
require "table2"
local fmt = require "fmt"

local function consolidate_sets(sets)
    local size = #sets
    local consolidated = table.rep(size, false)
    for i = 1, size - 1 do
        if !consolidated[i] then
            repeat
                local intersects = 0
                for j = i + 1, size do
                    if !consolidated[j] then
                        if !sets[i]:intersect(sets[j]):empty() then
                            sets[i]:merge(sets[j])
                            consolidated[j] = true
                            ++intersects
                        end
                    end
                end
            until intersects == 0
        end
    end
    return range(1, size):filter(|i| -> !consolidated[i]):reorder():map(|i| -> sets[i])
end

local unconsolidated_sets = {
    {set.of("A", "B"), set.of("C", "D")},
    {set.of("A", "B"), set.of("B", "D")},
    {set.of("A", "B"), set.of("C", "D"), set.of("D", "B")},
    {set.of("H", "I", "K"), set.of("A", "B"), set.of("C", "D"),
     set.of("D", "B"), set.of("F", "G", "H")}
}
for unconsolidated_sets as sets do
    fmt.print("Unconsolidated: %s", fmt.swrite(sets))
    fmt.print("Consolidated  : %s", fmt.swrite(consolidate_sets(sets)))
    print()
end