Lua秦九韶算法：多项式的降次求值

local function polySlow(coefs, x)
    local sum = 0
    for i, c in ipairs(coefs) do
        sum = sum + c * x ^ (#coefs - i)
    end
    return sum
end

local function horner(coefs, x)
    local r = 0
    for _, c in ipairs(coefs) do
        r = r * x + c
    end
    return r
end
local p = getplayerbyname("poly01")
sendmsg(p, 1, "x=2 时 " .. horner({2, 3, 1, 5, 7}, 2))