【入门夯实】裁决之杖兑换表：table赋值是引用不是拷贝

local function copyTbl(src)
    local dst = {}
    for k, v in pairs(src) do
        dst[k] = v
    end
    return dst
end
local EXCHANGE = { ["裁决之杖"] = 8000, ["骨玉权杖"] = 6000 }
local function makeDiscount(rate)
    local actTbl = copyTbl(EXCHANGE)
    for k, v in pairs(actTbl) do
        actTbl[k] = math.floor(v * rate)
    end
    return actTbl
end

local function deepCopy(src)
    if type(src) ~= "table" then
        return src
    end
    local dst = {}
    for k, v in pairs(src) do
        dst[k] = deepCopy(v)
    end
    return dst
end