有许多经典的排序算法，经常不用都快忘了，于是便用ruby实现了一下，加强记忆
冒泡排序
class Array
def bubble_sort
return self if self.size < 2
1.upto self.size - 1 do |i|
1.upto self.size - i do |j|
self[j], self[j - 1] = self[j - 1], self[j] if self[j] > self[j - 1]
end
end
end
self
end
1.9.3p327:> a = [1, 3, 53, 64, 5, 7, 98, 34]
=> [1, 3, 53, 64, 5, 7, 98, 34]
1.9.3p327:> a.bubble_sort
=> [98, 64, 53, 34, 7, 5, 3, 1]
快速排序
class Array
def quick_sort(a = self)
return a if a.size <= 1
middle = a.shift
left, right = a.partition {|elem| elem > middle}
quick_sort(left) + [middle] + quick_sort(right)
end
end