Lua原地归位：缺失正数的换位定位

local function findMiss(t)
    local seen = {}
    for _, v in ipairs(t) do seen[v] = true end   -- 额外内存
    local i = 1
    while seen[i] do i = i + 1 end
    return i
end

local function findMiss(t)
    local n = #t
    for i = 1, n do
        while t[i] >= 1 and t[i] <= n
            and t[t[i]] ~= t[i] do
            local v = t[i]
            t[i], t[v] = t[v], t[i]   -- 值归位到下标
        end
    end
    for i = 1, n do
        if t[i] ~= i then return i end
    end
    return n + 1
end
sendmsg(actor, 1, "缺失最小正数 " .. findMiss({3, 1, -2, 4}))