Lua猜数字：命中与存在的双提示

local function bulls(secret, guess)
    local a = 0
    for i = 1, #secret do
        if secret:sub(i, i) == guess:sub(i, i) then
            a = a + 1
        end
    end
    return a
end

local function hint(secret, guess)
    local a, sc, gc = 0, {}, {}
    for i = 1, #secret do
        local s, g = secret:sub(i, i), guess:sub(i, i)
        if s == g then a = a + 1
        else
            sc[s] = (sc[s] or 0) + 1
            gc[g] = (gc[g] or 0) + 1
        end
    end
    local b = 0
    for k in pairs(sc) do
        b = b + math.min(sc[k], gc[k] or 0)
    end
    return a, b
end
local p = getplayerbyname("guess01")
local a, b = hint("1807", "7810")
sendmsg(p, 1, a .. "A" .. b .. "B")