如何对数组中除特殊字符外的所有内容进行排序 - Ruby

Question

我正在尝试按字母顺序对一组字母进行排序，但将特殊字符保留在 ruby​​ 中的同一位置。

例如，

word = ["f", "a", "s", "t", "-", "c", "a", "r", "s"]

如何按字母顺序对整个内容进行排序，但将“-”保留在原处。如果我对现在的情况进行排序，那么“-”将出现在我不想要的前面。我尝试了十五种不同的方法，但我无法弄清楚。你能帮忙吗？

Answer 1

一些非常冗长的方法来解释你需要实现的逻辑。有一些“更清洁”的方法可以实现这一点，但我觉得这可以提供更多的理解。

为数组添加额外的特殊字符以获得更好的测试覆盖率：

let(:input) { ["f", "a", "s", "t", "-", "c", "a", "r", "s", "/"] }
let(:desired_output) { ["a", "a", "c", "f", "-", "r", "s", "s", "t", "/"] }

it "takes the input and gives the desired output" do
  expect(sort_alphanumeric_characters(input)).to eq(desired_output)
end

在数组上调用.map 和.select 以枚举值，然后调用.with_index，因为您需要保留索引以供以后使用。

def sort_alphanumeric_characters(word_as_array)
  # assuming you mean non-alphanumeric
  # collect those indicies which are 'special' characters
  # the regex matches the string with anything outside of the alphanumeric range. Note the '^'
  special_character_indicies = word_as_array.map.with_index { |val, indx| indx if val =~ /[^a-zA-Z0-9]/ }.compact
  # collect all characters by index that were not yielded as 'special'
  alphanumeric_array = word_as_array.select.with_index { |char, indx| char unless special_character_indicies.include? indx }
  # sort the alphanumeric array
  sorted_alphanumeric_array = alphanumeric_array.sort
  # use Array#insert to place the 'special' by index
  special_character_indicies.each do |special_indx|
    special_char = word_as_array[special_indx]
    sorted_alphanumeric_array.insert(special_indx, special_char)
  end
  # return desired output
  sorted_alphanumeric_array
end

Answer 2

我一发帖就得到了一道闪电（当它发生时我很喜欢）。这确实不是一个很好的解决方案，但它确实有效！

    def scramble_words(str)
      idx = 0 
      chars = str.delete("^a-z").chars
      first_ele = chars.shift
      last_ele = chars.pop
    
      str.chars.each_with_index {|c, i| idx = i if c =~ /[^a-z" "]/ }
    
      (first_ele + chars.sort.join  + last_ele).insert(idx, str[idx])
    
    end
    
    p scramble_words('card-carrying') == 'caac-dinrrryg'
    p scramble_words("shan't") == "sahn't"
    p scramble_words('-dcba') == '-dbca'