以下是我的代碼拋出的錯誤： File "python", line 39, in <module> File "python", line 8, in quicksort File "python", line 8, in quicksortTypeError: unsupported operand type(s) for -: 'NoneType' and 'int'下面是我的快速排序代碼：#!/usr/bin/python# -*- coding: utf-8 -*-def quicksort(arr, beg, end): if beg < end: pivot = partition(arr, beg, end) quicksort(arr, beg, pivot - 1) quicksort(arr, pivot + 1, end)def partition(arr, beg, end): left = beg right = end loc = beg while arr[loc] <= arr[right] and loc != right: right = right - 1 if loc == right: return loc elif arr[loc] > arr[right]: (arr[loc], arr[right]) = (arr[right], arr[loc]) loc = right while arr[loc] >= arr[left] and loc != left: left = left + 1 if loc == left: return loc elif arr[loc] < arr[left]: (arr[loc], arr[left]) = (arr[left], arr[loc]) loc = lefty = [9,7,5,1,5]quicksort(y, 0, 4)print(y)
2 回答
寶慕林4294392
TA貢獻2021條經驗 獲得超8個贊
您不能從不同類型（None和int）中減去 2 個變量。
你得到了，None因為不是所有的partition函數路徑都返回一些東西。
我return在它的末尾添加了一個對我來說最有意義的聲明：
#!/usr/bin/python
# -*- coding: utf-8 -*-
def quicksort(arr, beg, end):
if beg < end:
pivot = partition(arr, beg, end)
quicksort(arr, beg, pivot - 1)
quicksort(arr, pivot + 1, end)
def partition(arr, beg, end):
left = beg
right = end
loc = beg
while arr[loc] <= arr[right] and loc != right:
right = right - 1
if loc == right:
return loc
elif arr[loc] > arr[right]:
(arr[loc], arr[right]) = (arr[right], arr[loc])
loc = right
while arr[loc] >= arr[left] and loc != left:
left = left + 1
if loc == left:
return loc
elif arr[loc] < arr[left]:
(arr[loc], arr[left]) = (arr[left], arr[loc])
loc = left
return loc
y = [9,7,5,1,5]
quicksort(y, 0, 4)
print(y) # >>> [1, 5, 5, 7, 9]
但是，我沒有檢查每個場景的代碼邏輯的正確性。
您可以查看此線程以查看 Python 中快速排序的實現。
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