【Lua实战】强化费用保底返还：失败返还的期望值控制实现

local RETURN_RATE = { ore = 60, fee = 50 }
local function refundOnFail(actor, oreCost, feeCost)
    local player = class(actor)
    local backOre = math.floor(oreCost * RETURN_RATE.ore / 100)
    local backFee = math.floor(feeCost * RETURN_RATE.fee / 100)
    if backOre > 0 then
        giveitem(actor, "黑铁矿石", backOre)
    end
    if backFee > 0 then
        giveitem(actor, "金币", backFee)
    end
    sendmsg(actor, 0, "强化失败，返还黑铁矿石" .. backOre .. "个、金币" .. backFee)
end

local function expectedLoss(successRate, oreCost, feeCost)
    local failRate = 1 - successRate
    local loss = failRate * (oreCost * (1 - RETURN_RATE.ore / 100) + feeCost * (1 - RETURN_RATE.fee / 100))
    return math.floor(loss)
end