# Pastebin RVBJ1IgP
# frozen-string-literal: true
require 'benchmark'

str = 'AGTCAGTCAGTCTTTCCCAAAT'
keys = %w[A C G T]
n = 100000

Benchmark.bmbm do |x|
  x.report('count')            { n.times{ keys.map{|e| [e, str.count(e)] }.to_h } }
  x.report('reduce')           { n.times{ str.chars.reduce(Hash.new(0)){|a,c|a[c]+=1;a} } }
  x.report('group_by')         { n.times{ str.chars.group_by(&:itself).map{|k,v|[k,v.size]}.to_h } }
end

str = 'AGTCAGTCAGTCTTTCCCAAAT'.encode('US-ASCII') * 1000
keys = %w[A C G T]
n = 1000

Benchmark.bmbm do |x|
  x.report('large count')            { n.times{ keys.map{|e| [e, str.count(e)] }.to_h } }
  x.report('large reduce')           { n.times{ str.chars.reduce(Hash.new(0)){|a,c|a[c]+=1;a} } }
  x.report('large group_by')         { n.times{ str.chars.group_by(&:itself).map{|k,v|[k,v.size]}.to_h } }
end


__END__
Rehearsal --------------------------------------------
count      0.120000   0.000000   0.120000 (  0.126792)
reduce     0.590000   0.000000   0.590000 (  0.588076)
group_by   0.690000   0.000000   0.690000 (  0.690314)
----------------------------------- total: 1.400000sec

               user     system      total        real
count      0.110000   0.000000   0.110000 (  0.109941)
reduce     0.560000   0.000000   0.560000 (  0.568418)
group_by   0.660000   0.000000   0.660000 (  0.667988)


Rehearsal --------------------------------------------------
large count      0.050000   0.000000   0.050000 (  0.041615)
large reduce     4.770000   0.000000   4.770000 (  4.784031)
large group_by   3.940000   0.010000   3.950000 (  3.946272)
----------------------------------------- total: 8.770000sec

                     user     system      total        real
large count      0.050000   0.000000   0.050000 (  0.043490)
large reduce     4.720000   0.000000   4.720000 (  4.723694)
large group_by   3.940000   0.000000   3.940000 (  3.944049)