【安全加密】操作节奏画像：脚本外挂的间隔方差识别

local TS, DIF = {}, {}
local function sample(nm, now)
    local last = TS[nm]
    TS[nm] = now
    if not last then return nil end
    local q = DIF[nm] or {}
    if #q >= 64 then table.remove(q, 1) end
    table.insert(q, now - last)
    DIF[nm] = q
    return q
end
local function variance(q)
    local n = #q
    if n < 16 then return 999 end
    local sum = 0
    for i = 1, n do sum = sum + q[i] end
    local m = sum / n
    local v = 0
    for i = 1, n do v = v + (q[i] - m) ^ 2 end
    return v / n
end

local function judge(nm)
    local q = DIF[nm]
    if not q or #q < 16 then return end
    if variance(q) < 0.8 then
        local hit = (tonumber(getplayvar(nm, "HUMAN", "RHYTHM_HIT") or "0") or 0) + 1
        setplayvar(nm, "HUMAN", "RHYTHM_HIT", hit, 1)
        if hit >= 3 then
            sendluamsg(nm, 9218, 0, 0, 0, "captcha")
        end
    end
end