Another update from ingydotnet^djgoku

Task/Compare-sorting-algorithms-performance/Ruby/compare-sorting-algorithms-performance.rb

@@ -0,0 +1,93 @@
+class Array
+  def radix_sort(base=10)       # negative value is inapplicable.
+    ary = dup
+    rounds = (Math.log(ary.max)/Math.log(base)).ceil
+    rounds.times do |i|
+      buckets = Array.new(base){[]}
+      base_i = base**i
+      ary.each do |n|
+        digit = (n/base_i) % base
+        buckets[digit] << n
+      end
+      ary = buckets.flatten
+    end
+    ary
+  end
+
+  def quick_sort
+    return self  if size <= 1
+    pivot = sample
+    g = group_by{|x| x<=>pivot}
+    g.default = []
+    g[-1].quick_sort + g[0] + g[1].quick_sort
+  end
+
+  def shell_sort
+    inc = size / 2
+    while inc > 0
+      (inc...size).each do |i|
+        value = self[i]
+        while i >= inc and self[i - inc] > value
+          self[i] = self[i - inc]
+          i -= inc
+        end
+        self[i] = value
+      end
+      inc = (inc == 2 ? 1 : (inc * 5.0 / 11).to_i)
+    end
+    self
+  end
+
+  def insertion_sort
+    (1...size).each do |i|
+      value = self[i]
+      j = i - 1
+      while j >= 0 and self[j] > value
+        self[j+1] = self[j]
+        j -= 1
+      end
+      self[j+1] = value
+    end
+    self
+  end
+
+  def bubble_sort
+    (1...size).each do |i|
+      (0...size-i).each do |j|
+        self[j], self[j+1] = self[j+1], self[j]  if self[j] > self[j+1]
+      end
+    end
+    self
+  end
+end
+
+data_size = [1000, 10000, 100000, 1000000]
+data = []
+data_size.each do |size|
+  ary = *1..size
+  data << [ [1]*size, ary, ary.shuffle, ary.reverse ]
+end
+data = data.transpose
+
+data_type = ["set to all ones", "ascending sequence", "randomly shuffled", "descending sequence"]
+print "Array size:          "
+puts data_size.map{|size| "%9d" % size}.join
+
+data.each_with_index do |arys,i|
+  puts "\nData #{data_type[i]}:"
+  [:sort, :radix_sort, :quick_sort, :shell_sort, :insertion_sort, :bubble_sort].each do |m|
+    printf "%20s ", m
+    flag = true
+    arys.each do |ary|
+      if flag
+        t0 = Time.now
+        ary.dup.send(m)
+        printf "  %7.3f", (t1 = Time.now - t0)
+        flag = false  if t1 > 2
+      else
+        print "   --.---"
+      end
+    end
+    puts
+  end
+end