Array.include？多个值

Question

[2, 6, 13, 99, 27].include?(2)适用于检查数组是否包含一个值.但是,如果我想检查数组是否包含多个值列表中的任何一个,该怎么办？有没有比做更短的方式Array.include?(a) or Array.include?(b) or Array.include?(c) ...？

Answer 1

您可以采用两个数组的交集,看看它是否为空:

([2, 6, 13, 99, 27] & [2, 6]).any?

Answer 2

你可以使用Enumerable#any吗？带有代码块的方法,用于测试是否包含多个值.例如,要检查6或13:

[2, 6, 13, 99, 27].any? { |i| [6, 13].include? i }

Answer 3

我很感兴趣,看到这些不同的方法在性能上相比如何,与其说手头的问题,但更多的阵列VS交集,阵VS一套一般比较include?和include?VS index数组.我将编辑以添加建议的其他方法,如果您想查看不同的基准参数,请告诉我.

我希望看到更多的SO答案的基准测试.这并不困难或耗时,它可以提供有用的见解.我发现大部分时间都在准备测试用例.请注意,我已将要测试的方法放在模块中,因此如果要对其他方法进行基准测试,我只需要将该方法添加到模块中.

方法比较

module Methods
  require 'set'
  def august(a,b)    (a&b).any? end
  def gnome_inc(a,b) a.any? { |i| b.include? i } end
  def gnome_ndx(a,b) a.any? { |i| b.index i } end
  def gnome_set(a,b) bs=b.to_set; a.any? { |i| bs.include? i } end
  def vii_stud(a,b)  as, bs = Set.new(a), Set.new(b); as.intersect?(bs) end
end

include Methods
@methods = Methods.instance_methods(false)
  #=> [:august, :gnome_inc, :gnome_ndx, :gnome_set, :vii_stud]

测试数据

def test_data(n,m,c,r)
  # n: nbr of elements in a
  # m: nbr of elements in b
  # c: nbr of elements common to a & b
  # r: repetitions
  r.times.each_with_object([]) { |_,a|
    a << [n.times.to_a.shuffle, [*(n-c..n-c-1+m)].shuffle] }
end

d = test_data(10,4,2,2)
  #=> [[[7, 8, 0, 3, 2, 9, 1, 6, 5, 4], [11, 10,  9, 8]], 
  #    [[2, 6, 3, 4, 7, 8, 0, 9, 1, 5], [ 9, 11, 10, 8]]]
# Before `shuffle`, each of the two elements is:
  #=> [[0, 1, 2, 3, 4, 5, 6, 7, 8, 9], [8, 9, 10, 11]] 

def compute(d, m)
  d.each_with_object([]) { |(a,b),arr| arr << send(m, a, b) }
end  

compute(d, :august)
 #=> [true, true]

确认方法返回相同的值

d = test_data(1000,100,10,3)
r0 = compute(d, @methods.first) 
puts @methods[1..-1].all? { |m| r0 == compute(d, m) }
  #=> true

基准代码

require 'benchmark'

@indent = methods.map { |m| m.to_s.size }.max

def test(n, m, c, r, msg)
  puts "\n#{msg}"
  puts "n = #{n}, m = #{m}, overlap = #{c}, reps = #{r}"
  d = test_data(n, m, c, r)
  Benchmark.bm(@indent) do |bm|
    @methods.each do |m|
      bm.report m.to_s do
        compute(d, m)
      end
    end
  end
end

测试

n = 100_000
m = 1000
test(n, m,    0,  1, "Zero overlap")
test(n, m, 1000,  1, "Complete overlap")
test(n, m,    1, 20, "Overlap of 1")
test(n, m,    5, 20, "Overlap of 5")
test(n, m,   10, 20, "Overlap of 10")
test(n, m,   20, 20, "Overlap of 20")
test(n, m,   50, 20, "Overlap of 50")
test(n, m,  100, 20, "Overlap of 100")

Zero overlap
n = 100000, m = 1000, overlap = 0, reps = 1
                                 user     system      total        real
august                       0.010000   0.000000   0.010000 (  0.005491)
gnome_inc                    4.480000   0.010000   4.490000 (  4.500531)
gnome_ndx                    0.810000   0.000000   0.810000 (  0.822412)
gnome_set                    0.030000   0.000000   0.030000 (  0.031668)
vii_stud                     0.080000   0.010000   0.090000 (  0.084283)

Complete overlap
n = 100000, m = 1000, overlap = 1000, reps = 1
                                 user     system      total        real
august                       0.000000   0.000000   0.000000 (  0.005841)
gnome_inc                    0.010000   0.000000   0.010000 (  0.002521)
gnome_ndx                    0.000000   0.000000   0.000000 (  0.000350)
gnome_set                    0.000000   0.000000   0.000000 (  0.000655)
vii_stud                     0.090000   0.000000   0.090000 (  0.097850)

Overlap of 1
n = 100000, m = 1000, overlap = 1, reps = 20
                                 user     system      total        real
august                       0.110000   0.000000   0.110000 (  0.116276)
gnome_inc                   61.790000   0.100000  61.890000 ( 62.058320)
gnome_ndx                   10.100000   0.020000  10.120000 ( 10.144649)
gnome_set                    0.360000   0.000000   0.360000 (  0.357878)
vii_stud                     1.450000   0.050000   1.500000 (  1.501705)

Overlap of 5
n = 100000, m = 1000, overlap = 5, reps = 20
                                 user     system      total        real
august                       0.110000   0.000000   0.110000 (  0.113747)
gnome_inc                   16.550000   0.050000  16.600000 ( 16.728505)
gnome_ndx                    2.470000   0.000000   2.470000 (  2.475111)
gnome_set                    0.100000   0.000000   0.100000 (  0.099874)
vii_stud                     1.630000   0.060000   1.690000 (  1.703650)

Overlap of 10
n = 100000, m = 1000, overlap = 10, reps = 20
                                 user     system      total        real
august                       0.110000   0.000000   0.110000 (  0.112674)
gnome_inc                   10.090000   0.020000  10.110000 ( 10.131339)
gnome_ndx                    1.470000   0.000000   1.470000 (  1.478400)
gnome_set                    0.060000   0.000000   0.060000 (  0.062762)
vii_stud                     1.430000   0.050000   1.480000 (  1.476961)

Overlap of 20
n = 100000, m = 1000, overlap = 20, reps = 20
                                 user     system      total        real
august                       0.100000   0.000000   0.100000 (  0.108350)
gnome_inc                    4.020000   0.000000   4.020000 (  4.026290)
gnome_ndx                    0.660000   0.010000   0.670000 (  0.663001)
gnome_set                    0.030000   0.000000   0.030000 (  0.024606)
vii_stud                     1.380000   0.050000   1.430000 (  1.437340)

Overlap of 50
n = 100000, m = 1000, overlap = 50, reps = 20
                                 user     system      total        real
august                       0.120000   0.000000   0.120000 (  0.121278)
gnome_inc                    2.170000   0.000000   2.170000 (  2.236737)
gnome_ndx                    0.310000   0.000000   0.310000 (  0.308336)
gnome_set                    0.020000   0.000000   0.020000 (  0.015326)
vii_stud                     1.220000   0.040000   1.260000 (  1.259828)

Overlap of 100
n = 100000, m = 1000, overlap = 100, reps = 20
                                 user     system      total        real
august                       0.110000   0.000000   0.110000 (  0.112739)
gnome_inc                    0.720000   0.000000   0.720000 (  0.712265)
gnome_ndx                    0.100000   0.000000   0.100000 (  0.105420)
gnome_set                    0.010000   0.000000   0.010000 (  0.009398)
vii_stud                     1.400000   0.050000   1.450000 (  1.447110)

Answer 4

简单方法：

([2, 6] - [2, 6, 13, 99, 27]).empty?