Lua约数个数：因子成对的枚举上界

local function divisorsSlow(n)
    local c = 0
    for i = 1, n do
        if n % i == 0 then c = c + 1 end
    end
    return c
end

local function divisors(n)
    local c, i = 0, 1
    while i * i < n do
        if n % i == 0 then c = c + 2 end
        i = i + 1
    end
    if i * i == n then c = c + 1 end
    return c
end
local p = getplayerbyname("div01")
sendmsg(p, 1, "36 有 " .. divisors(36) .. " 个约数")