常见数据结构与算法的 Python 实现

1. 排序

def partition(seq):
pivot, seq = seq[0], seq[1:]
low = [x for x in seq if x <= pivot]
high = [x for x in seq if x not in low]
return low, pivot, high

def qsort(seq):
if len(seq) <= 1: return seq
low, pivot, high = partition(seq)
return qsort(low)+[pivot]+qsort(high)

def qsort(arr):
if len(arr) <= 1:
return arr
pivot = arr[len(arr)//2]
left = [x for x in arr if x < pivot]
middle = [x for x in arr if x == pivot]
right = [x for x in arr if x > pivot]
return qsort(left) + middle + qsort(right)