Quick sorting (Ruby)

I just learned Ruby. It happened that the algorithm teacher encouraged me to write algorithms in unfamiliar languages. I will use ruby ~~

Ruby is really amazing, and many intuitive methods can be used ..... Infinite worship ....

While I encountered an invalid multibyte char (US-ASCII) error, the solution is to add a # encoding: UTF-8 at the beginning

This error was asked by someone on stackoverflow. The answer Someone gave is:

Write# encoding: utf-8On
Top of that file. That changes the default encoding of all string/Regexp literals in that fileutf-8.

Reference: http://stackoverflow.com/questions/3678172/ruby-1-9-invalid-multibyte-char-us-ascii

Reference: Introduction to algorithms, github.com/kanwei

Common Quick Sort versions:

#encoding: utf-8#author: xu jin, 4100213#date: Oct 20, 2012#RandomizedQuickSort#to sort an array by using QuickSort#example:#The original array is：[10, 35, 25, 67, 69, 52, 24, 40, 69, 76, 6, 49]#The sorted array is: [6, 10, 24, 25, 35, 40, 49, 52, 67, 69, 69, 76]arrayInt = Array.newindex = 0while (index < 12)  arrayInt[index] = rand(100)  #produce 12 random number  index += 1endputs "The original array is：" + arrayInt.to_sdef QuickSort(arrayInt, first, last)  if first < last      middle = Partition(arrayInt, first, last)    QuickSort(arrayInt, first, middle - 1)    QuickSort(arrayInt, middle + 1, last)       end  enddef Partition(arrayInt, first, last)    x = arrayInt[last]  i = first - 1  for j in first .. (last - 1)    if arrayInt[j] <= x        i += 1       arrayInt[i], arrayInt[j] = arrayInt[j], arrayInt[i]  #exchange    end  end  arrayInt[i + 1], arrayInt[last] = arrayInt[last], arrayInt[i + 1]  return i + 1endQuickSort(arrayInt, 0, arrayInt.length-1)puts "The sorted array is: " + arrayInt.to_s

Randomization version of Quick Sort:

#encoding: utf-8#author: xu jin, 4100213#date: Oct 20, 2012#RandomizedQuickSort#to sort an array by using randomized QuickSort#example: #The original array is：[14, 47, 46, 49, 82, 76, 92, 22, 44, 81, 59, 61]#The sorted array is: [14, 22, 44, 46, 47, 49, 59, 61, 76, 81, 82, 92]arrayInt = Array.newindex = 0while (index < 12)  arrayInt[index] = rand(100)  #produce 12 random number  index += 1endputs "The original array is：" + arrayInt.to_sdef RandomizedQuickSort(arrayInt, first, last)  if first < last      middle = RandomizedPartition(arrayInt, first, last)    RandomizedQuickSort(arrayInt, first, middle - 1)    RandomizedQuickSort(arrayInt, middle + 1, last)       end  enddef RandomizedPartition(arrayInt, first, last)  i = rand(last - first + 1) + first   arrayInt[i], arrayInt[last] = arrayInt[last], arrayInt[i]  return Partition(arrayInt, first, last)  enddef Partition(arrayInt, first, last)    x = arrayInt[last]  i = first - 1  for j in first .. (last - 1)    if arrayInt[j] <= x        i += 1       arrayInt[i], arrayInt[j] = arrayInt[j], arrayInt[i]  #exchange    end  end  arrayInt[i + 1], arrayInt[last] = arrayInt[last], arrayInt[i + 1]  return i + 1endRandomizedQuickSort(arrayInt, 0, arrayInt.length-1)puts "The sorted array is: " + arrayInt.to_s

The quick sorting utilizes the random version of the Ruby syntax sugar:

#encoding: utf-8#author: xu jin, 4100213#date: Oct 20, 2012#RandomizedQuickSort#to sort an array by using randomized QuickSort#example: #The original array is：[14, 47, 46, 49, 82, 76, 92, 22, 44, 81, 59, 61]#The sorted array is: [14, 22, 44, 46, 47, 49, 59, 61, 76, 81, 82, 92]arrayInt = Array.newindex = 0while (index < 12)  arrayInt[index] = rand(100)  #produce 12 random number  index += 1endputs "The original array is：" + arrayInt.to_sdef RandomizedQuickSort(a)   i = rand(a.length)  a[i], a[a.length - 1] = a[a.length - 1], a[i]  (x=a.pop) ? RandomizedQuickSort(a.select{|i| i <= x}) + [x] + RandomizedQuickSort(a.select{|i| i > x}) : []  end puts "The sorted array is: " + RandomizedQuickSort(arrayInt).to_s