Ruby之散列与快排小程序

#自己动手写一个Hash.grep，在key或value中搜索匹配正则表达式的名/值对，输出出来。
animals=Hash['cat','111','dog','222','fish','fff']
#key match /[ia]/
results=animals.keys.grep(/[ia]/)
results.each{|key| print key,'=>',animals[key],"\n"}
#value match
keys=animals.keys
keys.each{|key|
	if /([0-9]+)/ =~ animals[key] then
		print key,'=>',animals[key],"\n"
	end
}
#尝试用最少的ruby语句实现快速排序
list=[9,2,3,7,0,1,4]
def quicksort(list) 
  return list if list.size <= 1 
  pivot = list.sample 
  left, right = list.partition { |e| e < pivot } 
  quicksort(left) + quicksort(right) 
end 
print quicksort(list),"\n"