python快排

思路来自算法图解, 比自己写的更pythonic。

def fun(list):
if len(list) < 2:
return list
else:
pivot = list[0]
low = [i for i in list[1:] if i <= pivot]
high = [i for i in list[1:] if i > pivot]
return fun(low) + [pivot] + fun(high)