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多段階選抜 (Ruby)(旧)

Last updated at Posted at 2014-08-02
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

最初の答案。上限固定。idxesで消す座標を得てから削除。
with_indexに引数を指定しているのでRuby 1.8.7とは互換性がありません。

hena24.rb
#!/usr/bin/env ruby
#http://qiita.com/Nabetani/items/1c83005a854d2c6cbb69
#http://nabetani.sakura.ne.jp/hena/ord24eliseq/
MAX=10000
sq=Hash[[*1..100].map{|e|[e**2,1]}]
cb=Hash[[*1..100].map{|e|[e**3,1]}]
if $0==__FILE__
    STDOUT.sync=true
    while gets
        input=$_.chomp.split('')
        a=[*1..MAX]
        input.each{|e|
            if e=='S'
                idxes=a.each.with_index.select{|f,i|sq.include?(f)}.map{|e|e.last+1}
                a=a.each.with_index.reject{|f,i|idxes.include?(i)}.map(&:first)
            elsif e=='s'
                idxes=a.each.with_index.select{|f,i|sq.include?(f)}.map{|e|e.last-1}
                a=a.each.with_index.reject{|f,i|idxes.include?(i)}.map(&:first)
            elsif e=='C'
                idxes=a.each.with_index.select{|f,i|cb.include?(f)}.map{|e|e.last+1}
                a=a.each.with_index.reject{|f,i|idxes.include?(i)}.map(&:first)
            elsif e=='c'
                idxes=a.each.with_index.select{|f,i|cb.include?(f)}.map{|e|e.last-1}
                a=a.each.with_index.reject{|f,i|idxes.include?(i)}.map(&:first)
            elsif e=='h'
                a=a.drop(100)
            else
                a=a.each.with_index(1).select{|f,i|i%e.to_i!=0}.map(&:first)
            end
        }
        puts a[0,10]*','
    end
end

解き直したもの。Enumeratorを使う。main中はreduce一個のみ。XY-sort( http://qiita.com/cielavenir/items/84e5cb1e5081bccdbbcd )と同じぐらいきれいに書けた。

Ruby 1.8.7: 70s
Ruby 2.0.0: 0.3s

hena24_enum.rb
#!/usr/bin/env ruby
#http://qiita.com/Nabetani/items/1c83005a854d2c6cbb69
#http://nabetani.sakura.ne.jp/hena/ord24eliseq/
if RUBY_VERSION<'1.9'
    module Math
        def self.cbrt(n)
            n**(1.0/3)+1e-9
        end
    end
end
def generate
    return to_enum(:generate) if !block_given?
    i=1
    loop{
        yield i
        i+=1
    }
end
def drop_prev_square(prev)
    return to_enum(:drop_prev_square,prev) if !block_given?
    a=prev.next
    b=prev.next
    loop{
        yield a if Math.sqrt(b).to_i**2!=b
        a,b=b,prev.next
    }
end
def drop_next_square(prev)
    return to_enum(:drop_next_square,prev) if !block_given?
    a=prev.next
    b=prev.next
    yield a
    loop{
        yield b if Math.sqrt(a).to_i**2!=a
        a,b=b,prev.next
    }
end
def drop_prev_cubic(prev)
    return to_enum(:drop_prev_cubic,prev) if !block_given?
    a=prev.next
    b=prev.next
    loop{
        yield a if Math.cbrt(b).to_i**3!=b
        a,b=b,prev.next
    }
end
def drop_next_cubic(prev)
    return to_enum(:drop_next_cubic,prev) if !block_given?
    a=prev.next
    b=prev.next
    yield a
    loop{
        yield b if Math.cbrt(a).to_i**3!=a
        a,b=b,prev.next
    }
end
def drop_num(n,prev)
    return to_enum(:drop_num,n,prev) if !block_given?
    i=0
    loop{
        i+=1
        a=prev.next
        yield a if i%n!=0
    }
end
def drop_cnt(n,prev)
    return to_enum(:drop_cnt,n,prev) if !block_given?
    i=0
    loop{
        i+=1
        a=prev.next
        yield a if i>n
    }
end
f={
    'S'=>Kernel.method(:drop_next_square),
    's'=>Kernel.method(:drop_prev_square),
    'C'=>Kernel.method(:drop_next_cubic),
    'c'=>Kernel.method(:drop_prev_cubic),
    'h'=>RUBY_VERSION<'1.9' ?
        lambda{|enum|drop_cnt(100,enum)} :
        Kernel.method(:drop_cnt).to_proc.curry[100],
}
('2'..'9').each{|e|f[e]=RUBY_VERSION<'1.9' ?
    lambda{|enum|drop_num(e.to_i,enum)} :
    Kernel.method(:drop_num).to_proc.curry[e.to_i]
}

if $0==__FILE__
    STDOUT.sync=true
    while gets
        puts $_.chomp.chars.reduce(generate){|s,e|f[e][s]}.take(10)*','
=begin
        enum=generate
        $_.chomp.chars.each{|e|
            if e=='S'
                enum=drop_next_square(enum)
            elsif e=='s'
                enum=drop_prev_square(enum)
            elsif e=='C'
                enum=drop_next_cubic(enum)
            elsif e=='c'
                enum=drop_prev_cubic(enum)
            elsif e=='h'
                enum=drop_cnt(100,enum)
            else
                enum=drop_num(e.to_i,enum)
            end
        }
        puts enum.take(10)*','
=end
    end
end
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