【高级技巧】并查集：分组关系的合并与查询封装

local parent = {}
local rank = {}
local function makeSet(name)
    parent[name] = name
    rank[name] = 0
end
local function find(name)
    if parent[name] ~= name then
        parent[name] = find(parent[name])
    end
    return parent[name]
end
local function union(a, b)
    local ra, rb = find(a), find(b)
    if ra == rb then
        return false
    end
    if rank[ra] < rank[rb] then
        ra, rb = rb, ra
    end
    parent[rb] = ra
    if rank[ra] == rank[rb] then
        rank[ra] = rank[ra] + 1
    end
    return true
end

makeSet("甲会")
makeSet("乙会")
makeSet("甲会一队")
union("甲会", "甲会一队")
print(find("甲会一队") == find("甲会"))