Lua三色旗：一次扫描的三区原地排序

local function countSort(colors)
    local c = {0, 0, 0}
    for _, v in ipairs(colors) do c[v] = c[v] + 1 end
    local out = {}
    for i = 1, #colors do
        out[i] = i <= c[1] and 1
            or (i <= c[1] + c[2] and 2 or 3)
    end
    return out
end

local function flagSort(a)
    local low, mid, high = 1, 1, #a
    while mid <= high do
        if a[mid] == 1 then
            a[low], a[mid] = a[mid], a[low]
            low = low + 1
            mid = mid + 1
        elseif a[mid] == 2 then
            mid = mid + 1
        else
            a[mid], a[high] = a[high], a[mid]
            high = high - 1
        end
    end
    return a
end
local p = getplayerbyname("flag01")
sendmsg(p, 1, table.concat(flagSort({3, 1, 2, 3, 1, 2}), ","))