谁能告诉我什么';Python中的合并排序有什么问题?
它给了我以下的错误,我知道这与左数组或右数组有时不存在这一事实有关。我只是不知道为什么会这样。错误:谁能告诉我什么';Python中的合并排序有什么问题?,python,algorithm,sorting,mergesort,Python,Algorithm,Sorting,Mergesort,它给了我以下的错误,我知道这与左数组或右数组有时不存在这一事实有关。我只是不知道为什么会这样。错误: File "/Users/lezoudali/Documents/Algorithms/sort.py", line 62, in merge while i < len(left) and j < len(right): TypeError: object of type 'NoneType' has no len() 文件“/Users/lezoudali/Docu
File "/Users/lezoudali/Documents/Algorithms/sort.py", line 62, in merge
while i < len(left) and j < len(right):
TypeError: object of type 'NoneType' has no len()
文件“/Users/lezoudali/Documents/Algorithms/sort.py”,第62行,合并中
而i
我的代码:
from random import randint
alist = [randint(1,50) for i in range(10)]
def merge(left, right):
i = j = 0
result = []
while i < len(left) and j < len(right):
if left[i] < right[j]:
result.append(left[i])
i += 1
else:
result.append(right[j])
j += 1
while i < len(left):
result.append(left[i])
i += 1
while j < len(right):
result.append(right[j])
j += 1
def mergesort(alist):
if len(alist) == 1:
return alist
mid = len(alist) // 2
left = mergesort(alist[:mid])
right = mergesort(alist[mid:])
return merge(left, right)
print mergesort(alist)
来自随机导入randint
alist=[randint(1,50)表示范围(10)内的i]
def合并(左、右):
i=j=0
结果=[]
而i
原来我没有从合并函数返回结果。所以函数是returnnone,这就是我遇到的问题。谢谢senderle
def merge(left, right):
i = j = 0
result = []
while i < len(left) and j < len(right):
if left[i] < right[j]:
result.append(left[i])
i += 1
else:
result.append(right[j])
j += 1
while i < len(left):
result.append(left[i])
i += 1
while j < len(right):
result.append(right[j])
j += 1
return result
def合并(左、右):
i=j=0
结果=[]
而i
您的merge
函数没有返回任何内容。您将数据从左侧
和右侧
保存到结果
,但没有返回
语句,合并
只返回无
。所以返回合并(左、右)
也返回无
。啊,是的,谢谢先生。:)