Hamming benchmarks - Style comparisons

hamming_benchmark_styles.rb

class Hamming
  def self.zip_count(s1, s2)
    s1.chars.
      zip(s2.chars).
      count { |c1, c2| c1 != c2 }
  end

  def self.for_loop(s1, s2)
    distance = 0

    for i in 0...s1.length
      if s1[i] != s2[i]
        distance = distance + 1
      end
    end
    distance
  end

  def self.indexes(s1, s2)
    distance = 0

    s1.chars.each_with_index do |j, i|
      distance = distance + 1 if s1[i] != s2[i]
    end
    distance
  end
end

require 'benchmark'

puts
puts "=== TIME - Short strings (25 chars) ==="
puts

short1 = "#{"A" * 23}TG"
short2 = "#{"A" * 23}CT"

Benchmark.bm do |x|
  x.report("Zip + Count    ") { 100_000.times { Hamming.zip_count(short1, short2) } }
  x.report("For Loop       ") { 100_000.times { Hamming.for_loop(short1, short2) } }
  x.report("Each with index") { 100_000.times { Hamming.indexes(short1, short2) } }
end

puts
puts "=== TIME - Medium strings (250 chars) ==="
puts

med1 = "#{"A" * 248}TG"
med2 = "#{"A" * 248}CT"

Benchmark.bm do |x|
  x.report("Zip + Count    ") { 100_000.times { Hamming.zip_count(med1, med2) } }
  x.report("For Loop       ") { 100_000.times { Hamming.for_loop(med1, med2) } }
  x.report("Each with index") { 100_000.times { Hamming.indexes(med1, med2) } }
end

puts
puts "=== TIME - Long strings (2500 chars) ==="
puts

long1 = "#{"A" * 2_448}TG"
long2 = "#{"A" * 2_448}CT"

Benchmark.bm do |x|
  x.report("Zip + Count    ") { 100_000.times { Hamming.zip_count(long1, long2) } }
  x.report("For Loop       ") { 100_000.times { Hamming.for_loop(long1, long2) } }
  x.report("Each with index") { 100_000.times { Hamming.indexes(long1, long2) } }
end

hamming_benchmark_styles.txt

=== TIME - Short strings (25 chars) ===               

       user     system      total        real         
Zip + Count      0.916516   0.000370   0.916886 (  0.916935)                                                 
For Loop         0.741585   0.000282   0.741867 (  0.741969)                                                 
Each with index  1.048152   0.000745   1.048897 (  1.049324)                                                 

=== TIME - Medium strings (250 chars) ===             

       user     system      total        real         
Zip + Count      7.439889   0.004716   7.444605 (  7.446956)                                                 
For Loop         6.939437   0.003735   6.943172 (  6.945046)                                                 
Each with index  9.205381   0.004338   9.209719 (  9.211600)                                                 

=== TIME - Long strings (2500 chars) ===              

       user     system      total        real         
Zip + Count     97.230279   0.130710  97.360989 ( 97.460118)                                                 
For Loop        68.952586   0.068595  69.021181 ( 69.065801)                                                 
Each with index 96.847159   0.118325  96.965484 ( 97.052869)