多段階選抜 (Lua)

多段階選抜	解答日	シリーズ:yieldの練習/ジェネレータを入れ子に/整数平方根・立方根の実装
問題		http://nabetani.sakura.ne.jp/hena/ord24eliseq/ https://qiita.com/Nabetani/items/1c83005a854d2c6cbb69
Ruby	2014/8/2(当日)	https://qiita.com/cielavenir/items/9f15e29b73ecf98968a5
C#/Python	2014/8/4	https://qiita.com/cielavenir/items/a1156e6a4f71ddbe5dcb
		ここから上はdrop_prev_square/drop_prev_cubicをまとめる前の答案
Go/C#/Ruby/Python	2014/8/5	https://qiita.com/cielavenir/items/2a685d3080862f2c2c47
PHP/JavaScript	2014/9/9	https://qiita.com/cielavenir/items/28d613ac3823afbf8407
VB	2014/9/10	https://qiita.com/cielavenir/items/cb7266abd30eadd71c04
D	2015/12/21	https://qiita.com/cielavenir/items/47c9e50ee60bef2847ec
Perl	2017/3/10	https://qiita.com/cielavenir/items/6dfbff749d833c0fd423
Lua	2017/3/13	https://qiita.com/cielavenir/items/c60fe7e8da73487ba062
C++20(TS)	2017/3/15	https://qiita.com/cielavenir/items/e1129ca185008f49cbab (MSVC) https://qiita.com/cielavenir/items/1cfa90d73d11bb7dc3d4 (clang)
F#	2017/3/17	https://qiita.com/cielavenir/items/a698d6a26824ff53de81
Boo/Nemerle	2017/5/13	https://qiita.com/cielavenir/items/e2a783f0fe4b0fe0ed48
Perl6	2017/5/15	https://qiita.com/cielavenir/items/656ea17fa96c865c4498
Kotlin	2017/5/25	https://qiita.com/cielavenir/items/9c46ce8d9d12e51de285
Crystal	2018/5/8	https://qiita.com/cielavenir/items/1815bfa6a860fd1f90db
MoonScript	2018/6/16	https://qiita.com/cielavenir/items/8b03cce0386f4537b5ad
Julia/Rust	2018/12/20	https://qiita.com/cielavenir/items/3ddf72b06d625da0c4a5
Nim	2018/12/26	https://qiita.com/cielavenir/items/5728944867e609fd52a7
Tcl	2018/12/31	https://qiita.com/cielavenir/items/76cbd9c2022b48c9a2c9
Pascal/Cobra	2019/1/16	https://qiita.com/cielavenir/items/81b81baf8dfc1f877903
Icon	2019/1/17	https://qiita.com/cielavenir/items/889622dcc721f5a4da24
Swift	2020/5/31	https://qiita.com/cielavenir/items/3b0b84a218e35d538f7f
Java/Groovy/Scala	2020/5/31	https://qiita.com/cielavenir/items/7f058203a8fd03b65870
V	2020/10/17	https://qiita.com/cielavenir/items/df30a6c101a97a713df5
Zig/Zen	2020/10/17	https://qiita.com/cielavenir/items/9cced9e4a94dcd70df0f
Pike	2020/11/2	https://qiita.com/cielavenir/items/3a8248f41611302b34fd
Vala/Smalltalk	2020/11/29	https://qiita.com/cielavenir/items/085dabe593cd916af5e8
Objective-C	2020/11/30	https://qiita.com/cielavenir/items/a1736e38789a3dd5cc5a
Ruby(Ractor)	2021/1/2	https://qiita.com/cielavenir/items/f493c6d512b63cc571cc
Python(_xxsubinterpreters)	2021/6/29	https://qiita.com/cielavenir/items/f1f581a055db918954f1
Falcon/Scheme	2021/9/5	https://qiita.com/cielavenir/items/c13d12cf44f0d17f4a94
Clojure/Lisp	2021/9/7	https://qiita.com/cielavenir/items/7458ba076f4e5bc0f196
(icbrtの実装に関する)補題	2017/5/11	整数除算であってもn/(x*y)はn/x/yに等しい(ことの証明) https://qiita.com/cielavenir/items/21a6711afd6be8c18c55

cbrtはlmathxパッケージを使用しています。不要になりました。

tyama_hena24_enum.lua

#!/usr/bin/env lua
-- http://qiita.com/Nabetani/items/1c83005a854d2c6cbb69
-- http://nabetani.sakura.ne.jp/hena/ord24eliseq/

-- require 'mathx' -- luarocks install lmathx

function isqrt(n)
    if n<=0 then
        return 0
    end
    if n<4 then
        return 1
    end
    local x=0
    local y=n
    while x~=y and x+1~=y do
        x=y
        y=(n//y+y)//2
    end
    return x
end
function icbrt(n)
    if n<0 then
        return -icbrt(-n)
    end
    if n==0 then
        return 0
    end
    if n<8 then
        return 1
    end
    local x=0
    local y=n
    while x~=y and x+1~=y do
        x=y
        y=(n//y//y+y*2)//3
    end
    return x
end

function generate()
    return coroutine.create(function()
        local i=1
        while true do
            coroutine.yield(i)
            i=i+1
        end
    end)
end
function drop_prev(check,prev)
    return coroutine.create(function()
        local a,b
        _,a=coroutine.resume(prev)
        _,b=coroutine.resume(prev)
        while true do
            if not check(b) then
                coroutine.yield(a)
            end
            a=b
            _,b=coroutine.resume(prev)
        end
    end)
end
function drop_next(check,prev)
    return coroutine.create(function()
        local a,b
        _,a=coroutine.resume(prev)
        _,b=coroutine.resume(prev)
        coroutine.yield(a)
        while true do
            if not check(a) then
                coroutine.yield(b)
            end
            a=b
            _,b=coroutine.resume(prev)
        end
    end)
end
function drop_n(check,n,prev)
    return coroutine.create(function()
        local i=0,a
        while true do
            i=i+1
            _,a=coroutine.resume(prev)
            if not check(i,n) then
                coroutine.yield(a)
            end
        end
    end)
end

function is_sq(n)
    -- local x=math.floor(math.sqrt(n))
    local x=isqrt(n)
    return x*x==n
end
function is_cb(n)
    -- local x=math.floor(math.cbrt(n))
    local x=icbrt(n)
    return x*x*x==n
end
function is_multiple(i,n)
    return i%n==0
end
function is_le(i,n)
    return i<=n
end

local f={
    ['S']=function(e) return drop_next(is_sq,e) end,
    ['s']=function(e) return drop_prev(is_sq,e) end,
    ['C']=function(e) return drop_next(is_cb,e) end,
    ['c']=function(e) return drop_prev(is_cb,e) end,
    ['h']=function(e) return drop_n(is_le,100,e) end,
}
local i,r
for i=2,9 do
    f[tostring(i)]=function(e) return drop_n(is_multiple,i,e) end
end
local line=io.read('*line')
while line~=nil do
    local g=generate()
    for c in line:gmatch('.') do
        g=f[c](g)
    end
    for i=1,10 do
        if i>1 then
            io.write(',')
        end
        _,r=coroutine.resume(g)
        io.write(r)
    end
    io.write("\n")
    io.flush()
    line=io.read('*line')
end