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我将以下方法放在一起，以便 (1) 在数组中生成一个斐波那契序列，直到特定索引值，然后 (2) 返回给定索引的该序列中所有值的乘积。

当我将 master_num 值增加到 4 以上时，我的问题似乎出现了。在此之前，序列生成和产品方法都有效。我很确定我的问题与我脑海中关于 Ruby 如何索引序列数组的错误有关......

require 'pry'  #optional, i use pry to debug

master_num = 5

def gen_fib_sequence_up_to_index num
  rec_gen_fib_values num, []
end

def rec_gen_fib_values num, full_array
  start_array = [1,1]
  count = 0

  if num < start_array.size
    num
  end

  until start_array.size == num
    next_element = start_array[count] + start_array[count + 1]
    start_array.push(next_element)
    count += 1
  end
  return start_array
end

p gen_fib_sequence_up_to_index master_num

def fib_sequence_product sequence_array
  product = 1
  sequence_array.each do |i|
    product = product * sequence_array[i]
    #binding.pry
  end
  product
end

p fib_sequence_product gen_fib_sequence_up_to_index master_num

非常感谢您的意见和建议。

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1 回答 1

2 
def fib_sequence_product sequence_array
  product = 1
  sequence_array.each do |i|
    product = product * sequence_array[i]
    #binding.pry
  end
  product
end

在块i中不是索引，而是实际值。这应该有效：

def fib_sequence_product sequence_array
  product = 1
  sequence_array.each do |i|
    product = product * i # or product *= i or ...
  end
  product
end

生成带有斐波那契数的数组和计算乘积都可以不那么冗长。

于 2013-07-15T18:23:57.793 回答