在Ruby中的Hash反转？ [英] Hash invert in Ruby?

问题描述

我已经得到了格式的哈希值：

  {键1 =＆GT; [A，B，C]键2 =＆GT; [D，E，F]}
 

和我想结束了：

  {a =＆GT;键1，B =＆GT;键1，C =＆GT;键1，D =＆GT; KEY2 ...}
 

什么是实现这一目标的最简单的方法？

我使用Ruby on Rails的。

更新

OK，我设法提取服务器日志的真正对象，它正在通过AJAX推。

 参数：{身份=＆GT; {1=＆GT;1，14]，2=＆GT;7， 12，8，13]}}
 

解决方案

 散= {：键1 =＆GT; [一，B，C]，：键2 =＆GT; [D，E，F]}
 

第一个变种

  hash.map {| K，V | v.map {| F | {F =＆GT; ķ}}}。压扁
＃=＆GT; [{一个=＆GT;：KEY1}，{B=＆GT;：KEY1}，{C=＆GT;：KEY1}，{D=＆GT;：键2}，{E= ＆GT;：键2}，{F=＆GT;：KEY2}]
 

或

  hash.inject（{}）{| H，（K，V）| v.map {| F | H [F] = K}; H}
＃=＆GT; {一个=＆GT;：KEY1，B=＆GT;：KEY1，C=＆GT;：KEY1，D=＆GT;：KEY2，e的= GT;：KEY2，F= ＆GT;：键2}
 

UPD

好了，你的哈希值：

 哈希= {地位=＆GT; {1=＆GT;1，14]，2=＆GT;7， 12，8，13]}}
哈希[身份]注入（{}）{| H，（K，V）| v.map {| F | H [F] = K}; H}
＃=＆GT; {12=＆gt;中2，7=＆gt;中2，13=＆gt;中2，8=＆gt;中2，14=＆gt;中1 ，1=＆gt;中1}
 

I've got a hash of the format:

{key1 => [a, b, c], key2 => [d, e, f]}

and I want to end up with:

{ a => key1, b => key1, c => key1, d => key2 ... }

What's the easiest way of achieving this?

I'm using Ruby on Rails.

UPDATE

OK I managed to extract the real object from the server log, it is being pushed via AJAX.

  Parameters: {"status"=>{"1"=>["1", "14"], "2"=>["7", "12", "8", "13"]}}

解决方案

hash = {:key1 => ["a", "b", "c"], :key2 => ["d", "e", "f"]}

first variant

hash.map{|k, v| v.map{|f| {f => k}}}.flatten
#=> [{"a"=>:key1}, {"b"=>:key1}, {"c"=>:key1}, {"d"=>:key2}, {"e"=>:key2}, {"f"=>:key2}] 

or

hash.inject({}){|h, (k,v)| v.map{|f| h[f] = k}; h}
#=> {"a"=>:key1, "b"=>:key1, "c"=>:key1, "d"=>:key2, "e"=>:key2, "f"=>:key2} 

UPD

ok, your hash is:

hash = {"status"=>{"1"=>["1", "14"], "2"=>["7", "12", "8", "13"]}}
hash["status"].inject({}){|h, (k,v)| v.map{|f| h[f] = k}; h}
#=> {"12"=>"2", "7"=>"2", "13"=>"2", "8"=>"2", "14"=>"1", "1"=>"1"}

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