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获取与最小数量匹配的哈希

hash ruby

-1

Pete J · 技术社区 · 7 年前

我有一个哈希数组:

arr_of_hsh =[
  {minimum_quantity: "250", cost: "1.5600"},
  {minimum_quantity: "500", cost: "1.3500"},
  {minimum_quantity: "1000", cost: "1.1800"},
  {minimum_quantity: "2500", cost: "1.0200"}
]

给定一定数量,我想得到其值为 :minimum_quantity

{minimum_quantity: "250", cost: "1.5600"}

如果金额为1000:

{minimum_quantity: "1000", cost: "1.1800"}

2 回复 | 直到 7 年前

1

3

Ursus 7 年前

保持您的数据结构不变,我会这样说

 arr_of_hsh.select { |item| item[:minimum_quantity].to_i <= quantity }.
   max_by { |item| item[:minimum_quantity].to_i }

2

1

Cary Swoveland 7 年前

def f(arr, qty)
  h = arr.min_by do |h|
    n = h[:minimum_quantity].to_i
    n <= qty ? (qty-n) : Float::INFINITY
  end
  h[:minimum_quantity].to_i <= qty ? h : nil 
end

(100..1100).step(100).each { |qty| puts "#{qty}: #{f(arr_of_hsh, qty)}" }
 100: nil
 200: nil
 300: {:minimum_quantity=>"250",  :cost=>"1.5600"}
 400: {:minimum_quantity=>"250",  :cost=>"1.5600"}
 500: {:minimum_quantity=>"500",  :cost=>"1.3500"}
 600: {:minimum_quantity=>"500",  :cost=>"1.3500"}
 700: {:minimum_quantity=>"500",  :cost=>"1.3500"}
 800: {:minimum_quantity=>"500",  :cost=>"1.3500"}
 900: {:minimum_quantity=>"500",  :cost=>"1.3500"}
1000: {:minimum_quantity=>"1000", :cost=>"1.1800"}
1100: {:minimum_quantity=>"1000", :cost=>"1.1800"}

arr_of_hsh 阿鲁的阿鲁 减少价值 arr_by_hsh[:minimum_quantity.to_i Enumerable#find

def f(arr, qty)
  h = arr.find { |h| h[:minimum_quantity].to_i <= qty }
end

arr = arr_of_hsh.sort_by { |h| -h[:minimum_quantity].to_i }
  #=> [{:minimum_quantity=>"2500", :cost=>"1.0200"},
  #    {:minimum_quantity=>"1000", :cost=>"1.1800"}, 
  #    {:minimum_quantity=>"500", :cost=>"1.3500"},
  #    {:minimum_quantity=>"250", :cost=>"1.5600"}]
(100..1100).step(100).each { |qty| puts "#{qty}: #{f(arr, qty)}" }
  #=> (same as above)