我需要检查一个散列数组,每个散列包含一个标签和一个数据数组。最终结果将是一个连接字符串,首先是label,然后是对应于该label的数据。
哈希的输入数组如下所示:
[{label: "first", data: [1, 2]}, {label: "second", data: [3, 4, 5]}, {label: "third", data: []}, {label: "fourth", data: [6]}]
在这个例子中,max_returns应该是类似于:10

def round_robin(arr, max_returns)
  result = ''
  i = 0 # number of grabbed elements
  j = 0 # inner array position
  k = 0 # outer array position
  l = 0 # number of times inner array length has been exceeded
  while i < max_returns do
    if k >= arr.length
      j += 1
      k = 0
    end
    element = arr[k]
    if element[:data].empty?
      k += 1
      next
    end

    if j >= element[:data].length
      l += 1
      k += 1

      if l > arr.length && i < max_returns
        break
      end
      next
    end
    result += element[:label] + ': ' + element[:data][j].to_s + ', '
    i += 1
    k += 1
  end
  result
end

根据上述输入,输出应为:
"first: 1, second: 3, fourth: 6, first: 2, second: 4, second: 5"
另外:max_returns是检索结果总数的最大值。因此,如果我的示例有一个max_returns = 3,那么输出应该是:
"first: 1, second: 3, fourth: 6"
问:有没有一种更好,或者更有效的方法以循环方式从多个数组中获取数据?

最佳答案

这将起作用:

arr = [{ label: "first",  data: [1, 3] },
       { label: "second", data: [3, 4, 5] },
       { label: "third",  data: [] },
       { label: "fourth", data: [6] }]

results = []
arr.each do |h|
  h[:data].each_with_index do |d, i|
    results[i] ||= []
    results[i] << "#{h[:label]}: #{d}"
  end
end

results.flatten.join(', ')
#=> "first: 1, second: 3, fourth: 6, first: 3, second: 4, second: 5"

10-05 20:31
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