Lua缺失数字：求和作差的定位

local function missingSum(a)
    local n = #a + 1
    local total = n * (n + 1) / 2
    local s = 0
    for _, v in ipairs(a) do s = s + v end
    return total - s
end

local function missingSwap(a)
    for i = 1, #a do
        while a[i] <= #a and a[a[i]] ~= a[i] do
            local j = a[i]
            a[i], a[j] = a[j], a[i]
        end
    end
    for i = 1, #a do
        if a[i] ~= i then return i end
    end
    return #a + 1
end
local p = getplayerbyname("miss01")
sendmsg(p, 1, missingSum({1, 2, 4, 5}) .. "/" .. missingSwap({3, 1, 4, 5}))