Ruby 在散列中查找重复的键？

为了简化事情，假设我有下面的散列

我想找到多个散列中的键以及散列的名称。因此，理想情况下，我希望以

A is also in  a
A is also in  b
B is also in  a
B is also in  b
D is also in  b
D is also in  c
E is also in  b
E is also in  c

我能想到的唯一方法是：将所有键放在一个数组中，排序，删除唯一的元素，搜索包含剩余数组元素的每个哈希

我想这有点复杂和粗糙

问题

有没有更简单的方法跨哈希查找重复键

!/usr/bin/ruby                                                                                          

require 'ap'

a = {}
b = {}
c = {}

a["A"] = 1
a["B"] = 1
a["C"] = 1

b["A"] = 1
b["B"] = 1
b["D"] = 1
b["E"] = 1

c["D"] = 1
c["E"] = 1
c["F"] = 1

---

要查找具有特定键的哈希，可以执行以下操作

def find_key_in list_of_hashes, key
  list_of_hashes.select { |one_hash| one_hash.detect { |k,v| k == key }}
end

可以这样称呼：

irb(main):016:0> find_key_in [{a: 3, b: 2}, {b: 3, x: 4} ], :x
=> [{:b=>3, :x=>4}]

打印哈希值的名称是一个难题

像这样的

arr = { 'a' => a, 'b' => b, 'c' =>c}
#=> {"a"=>{"A"=>1, "B"=>1, "C"=>1}, "b"=>{"A"=>1, "B"=>1, "D"=>1, "E"=>1}, "c"=>{"D"=>1, "E"=>1, "F"=>1}}

def my_method(letter, arr)
 arr.map { |el|  "#{letter} is in #{el[0]}" if !el[1]["#{letter}"].nil? }.compact
end

例如：

my_method("A", arr)
#=> ["A is in a", "A is in b"]

---

您可以构建另一个散列来存储每个键及其散列：

keys = Hash.new { |hash, key| hash[key] = [] }
a.each_key { |k| keys[k] << :a }
b.each_key { |k| keys[k] << :b }
c.each_key { |k| keys[k] << :c }

要获得预期输出，请执行以下操作：

keys.each do |key, hashes|
  next if hashes.size < 2
  hashes.each { |hash| puts "#{key} is also in #{hash}" }
end

---

你试过什么吗？你能分享一下你的努力吗？哈希的名字是什么？哈希在Ruby中没有名称。

keys.each do |key, hashes|
  next if hashes.size < 2
  hashes.each { |hash| puts "#{key} is also in #{hash}" }
end

A is also in a
A is also in b
B is also in a
B is also in b
D is also in b
D is also in c
E is also in b
E is also in c