Question

需要为给定长度的给定字符串辩护，

ss = "There is an example to make Justify the text us"

Total length  = 50

必需的输出：

ss = "There  is an example to make Justify the  text  us"

此处字符串的长度调整为50个字符，在第一个字符“那里”之后添加间距，最后一个字符“我们”，“文本”。

尝试过，

qw = ""
string.split(" ").each_with_index do |x,i|
 qw = qw + " " + x 

end

但无法添加空间

Answer 1

试试这个，

str = 'There is an example to make Justify the text us'

words = str.split
width, remainder = (50 - words.map(&:length).inject(:+)).divmod(words.length - 1)
width, remainder = 1, 0 if width.zero? # take care of long lines
words.take(words.length - 1).each { |word| width.times { word << 32 }}
words.take(words.length - 1).shuffle.take(remainder).each { |word| word << 32 }
p words.join

这是如何运作的？

将字符串拆分为单词
计算空格宽度和余数k
将空格宽度附加到所有单词但最后一个
在k字

Answer 2

您的示例代码无效的原因是split使用了分隔符。

'a b c'.split.to_a #=> ['a', 'b', 'c']

当您手动重新组合字符串时，您需要在消耗分隔空间的位置添加单个空格（），从而产生相同的字符串。

根据评论的建议，您还没有向我们提供有关您希望如何处理此问题的足够信息。如果只有一个单词，会发生什么？如果我们有比行更多的字符怎么办？你想如何减重空间？你需要考虑文本的渲染宽度吗？这很快就变成了一个更复杂的项目。

但请注意，大多数视图 - 无论是移动设备，网络设备还是外壳设备 - 都有方法可以证明您可以使用的文本效果很好。

所有人都说，这是一个忽略边缘情况的工作实例：

input = "There is an example to make Justify the text us"
words = input.split
spaces_needed = 50 - input.scan(/[^ ]/).length
spaces_per_word = Float(spaces_needed) / (words.count - 1)

words.each_with_index.map do |word, i|
  word += ' ' if (spaces_per_word * (i + 1)) % 1 == 0
  word
end.join(' ')

Answer 3

假设你想先在最后一个单词中添加空格，然后再到第一个单词，再到倒数第二个单词等等：

def justify(str, length)
  words = str.split(/\s+/)
  cnt = words.size - 1
  return str if cnt < 1
  return str if str.size >= length

  diff = length - str.size
  base = diff / cnt + 1
  rest = diff % cnt

  cnt.times.each.with_index do |word, i|
    r = [i + 1, cnt - i - 1].min * 2 <= rest && rest > 0 ? 1 : 0
    rest -= r
    words[i] << " " * (base + r)
  end
  words.join
end

justify("There is an example to make Justify the text us", 50)
#=> "There  is an example to make Justify the  text  us"

justify("One more example", 50)
#=> "One                  more                  example"

justify("Or this", 50)
#=> "Or                                            this"

justify("Example", 50)
#=> "Example"

justify("There is an example to make Justify the very long text us", 50)
#=> "There is an example to make Justify the very long text us"

Answer 4

这是一种相当可读的方法：

def padString (str,width)
    words = str.split.map{|s|s+" "}      # words single spaced
    padding = width-words.join.length+1  # how much needs adding?
    locations = words.size - 1           # places space can be added
    return str if padding<0 or words==[] # abort if string too long or empty
    padding.times {
        words[rand(locations)] += " "    # append space to random location
    }
    words.join.strip!                    # reconstitute the string
end

它会随机添加填充，因此每次都会得到不同的行：

padString("There is an example to make Justify the text us",50)
=> "There is an  example to make Justify  the text  us"

padString("There is an example to make Justify the text us",50)
=> "There is an example  to make Justify the   text us"

padString("hey you",50)
=> "hey                                            you"

padString("hey",50)
=> "hey"

证明字符串红宝石

4 个答案: