拆分的數組子陣

Question

我有字符數組，看起來像這樣：

chars = ["x", "o", "o", "x", "x", "o", "o", "x", "x", "x", "o", "o"] 

我需要連續字符的數量和字符的索引。它應該是這樣的：

[ 
    { index: 0, length: 1 }, # "x" 
    { index: 1, length: 2 }, # "o", "o" 
    { index: 3, length: 2 }, # "x", "x" 
    { index: 5, length: 2 }, # "o", "o" 
    { index: 7, length: 3 }, # "x", "x", "x" 
    { index: 10, length: 2 } # "o", "o" 
] 

是否有一個簡單的方法來實現這一目標？

Answer 1

不知道你是否可以簡單地稱呼它，但這是一個單線的方式。結果數組的格式爲[index, length]。

chars.each_with_index.chunk {|i, _| i}.map {|_, y| [y.first.last, y.length]} 
#=> [[0, 1], [1, 2], [3, 2], [5, 2], [7, 3], [10, 2]] 

Answer 2

兩個人做的方式：

使用Emumerable＃slice_when（V.2.2 +）

count = 0 
arr = chars.slice_when { |a,b| a != b }.map do |arr| 
    sz = arr.size 
    h = { index: count, length: sz } 
    count += sz 
    h 
end 
    #=> [{:index=>0, :length=>1}, {:index=>1, :length=>2}, {:index=>3, :length=>2}, 
    # {:index=>5, :length=>2}, {:index=>7, :length=>3}, {:index=>10, :length=>2}] 

使用了反向引用

count = 0 
arr = chars.join.scan(/((.)\2*)/).map do |run, _| 
    sz = run.size 
    h = { index: count, length: sz } 
    count += sz 
    h 
end 
    #=> [{:index=>0, :length=>1}, {:index=>1, :length=>2}, {:index=>3, :length=>2}, 
    # {:index=>5, :length=>2}, {:index=>7, :length=>3}, {:index=>10, :length=>2}] 

正則表達式