对 python 中的无序列表 class 进行排序?解决方案?
Sort a unordered list class in python? solution?
我有一个这样的无序列表 class:
from node import Node
class UnorderedList:
"""
Unordered list
"""
def __init__(self):
self.head = None
def is_empty(self):
return self.head == None
def __len__(self):
"""
returns the length of the list O(1)
"""
return self.size()
def add(self, item):
"""
Add item to list
"""
temp = Node(item)
temp.set_next(self.head)
self.head = temp
def size(self):
"""
Return size of list
"""
current = self.head
count = 0
while current != None:
count = count + 1
current = current.get_next()
return count
def set(self, index, newdata):
"""
Set node-data in list at specific index
"""
current = self.head
previous = None
for i in range(index):
previous = current
current = current.get_next()
if current != None:
temp = Node(newdata)
temp.set_next(current)
if previous is None:
self.head = temp
else:
previous.set_next(temp)
else:
raise("index out of range")
def getIndex(self, item):
"""get the index of an item, assume the first one (head pointing to)
is 0"""
index = 0
current = self.head
found = False
while current != None:
if current.get_data() == item:
found = True
break
else:
current = current.get_next()
index += 1
if not found:
index = None
return index
def get(self, index):
"""
Returns node data based on index
"""
current = self.head
for i in range(index):
current = current.get_next()
if current != None:
return current.get_data()
else:
raise("index out of range")
def search(self, item):
"""
Returns True if item found, else return False
"""
# Här ska du returnera en bool (True/False)
# beroende på om 'item' finns i listan
current = self.head
found = False
while current != None and not found:
if current.get_data() == item:
found = True
else:
current = current.get_next()
return found
def print_list(self):
"""
Prints each item in list
"""
# Traversera listan och gör en print() på varje element
result = "["
node = self.head
if node != None:
result += str(node.data)
node = node.next
while node:
result += ", " + str(node.data)
node = node.next
result += "]"
return result
def remove(self, item):
"""
Removes item from list
"""
current = self.head
previous = None
found = False
while not found:
if current.get_data() == item:
found = True
else:
previous = current
current = current.get_next()
if previous == None:
self.head = current.get_next()
else:
previous.set_next(current.get_next())
我想创建一个 class 列表,然后我可以使用我的 "bubblesort" 函数对列表进行排序。
我的 "bubblesort" 函数如下所示:
def bubble_sort(items):
""" Bubble sort """
Size = items.size()
for i in range(Size):
for j in range(Size-1-i):
if items.get(j) > items.get(j+1):
tmps = items.get(j+1)
items.set(j, items.get(j+1))
items.set(j+1, tmps)
return items
现在让我们创建一个列表:
// create the list
myListTwo = UnorderedList()
// Add the elements to the list
myListTwo.add(4)
myListTwo.add(50)
myListTwo.add(6)
myListTwo.add(10)
myListTwo.add(60)
//print the list :
print(myListTwo.print_list())
[60, 10, 6, 50, 4]
在这个阶段一切都很好,但问题是当我想用我的 bubble_sort 函数对列表进行排序时,我得到了这个结果:
// bubble_sort my list
sorte = bubble_sort(myListTwo)
//print the list
print(sorte.print_list())
[10, 10, 10, 10, 60, 10, 6, 50, 4]
有什么想法吗?
Thanx/Georges
因此,您的实施有两个问题。
第一个是冒泡排序的内部代码。改变这个
tmps = items.get(j+1)
到
tmps = items.get(j)
有关交换的更多信息,请参阅此处 Python Simple Swap Function
第二个问题是set方法。你应该删除这个
temp = Node(newdata)
temp.set_next(current)
if previous is None:
self.head = temp
else:
previous.set_next(temp)
你应该这样写
current.set_data(newData)
(我不知道你是如何实现节点的class)
我有一个这样的无序列表 class:
from node import Node
class UnorderedList:
"""
Unordered list
"""
def __init__(self):
self.head = None
def is_empty(self):
return self.head == None
def __len__(self):
"""
returns the length of the list O(1)
"""
return self.size()
def add(self, item):
"""
Add item to list
"""
temp = Node(item)
temp.set_next(self.head)
self.head = temp
def size(self):
"""
Return size of list
"""
current = self.head
count = 0
while current != None:
count = count + 1
current = current.get_next()
return count
def set(self, index, newdata):
"""
Set node-data in list at specific index
"""
current = self.head
previous = None
for i in range(index):
previous = current
current = current.get_next()
if current != None:
temp = Node(newdata)
temp.set_next(current)
if previous is None:
self.head = temp
else:
previous.set_next(temp)
else:
raise("index out of range")
def getIndex(self, item):
"""get the index of an item, assume the first one (head pointing to)
is 0"""
index = 0
current = self.head
found = False
while current != None:
if current.get_data() == item:
found = True
break
else:
current = current.get_next()
index += 1
if not found:
index = None
return index
def get(self, index):
"""
Returns node data based on index
"""
current = self.head
for i in range(index):
current = current.get_next()
if current != None:
return current.get_data()
else:
raise("index out of range")
def search(self, item):
"""
Returns True if item found, else return False
"""
# Här ska du returnera en bool (True/False)
# beroende på om 'item' finns i listan
current = self.head
found = False
while current != None and not found:
if current.get_data() == item:
found = True
else:
current = current.get_next()
return found
def print_list(self):
"""
Prints each item in list
"""
# Traversera listan och gör en print() på varje element
result = "["
node = self.head
if node != None:
result += str(node.data)
node = node.next
while node:
result += ", " + str(node.data)
node = node.next
result += "]"
return result
def remove(self, item):
"""
Removes item from list
"""
current = self.head
previous = None
found = False
while not found:
if current.get_data() == item:
found = True
else:
previous = current
current = current.get_next()
if previous == None:
self.head = current.get_next()
else:
previous.set_next(current.get_next())
我想创建一个 class 列表,然后我可以使用我的 "bubblesort" 函数对列表进行排序。 我的 "bubblesort" 函数如下所示:
def bubble_sort(items):
""" Bubble sort """
Size = items.size()
for i in range(Size):
for j in range(Size-1-i):
if items.get(j) > items.get(j+1):
tmps = items.get(j+1)
items.set(j, items.get(j+1))
items.set(j+1, tmps)
return items
现在让我们创建一个列表:
// create the list
myListTwo = UnorderedList()
// Add the elements to the list
myListTwo.add(4)
myListTwo.add(50)
myListTwo.add(6)
myListTwo.add(10)
myListTwo.add(60)
//print the list :
print(myListTwo.print_list())
[60, 10, 6, 50, 4]
在这个阶段一切都很好,但问题是当我想用我的 bubble_sort 函数对列表进行排序时,我得到了这个结果:
// bubble_sort my list
sorte = bubble_sort(myListTwo)
//print the list
print(sorte.print_list())
[10, 10, 10, 10, 60, 10, 6, 50, 4]
有什么想法吗?
Thanx/Georges
因此,您的实施有两个问题。
第一个是冒泡排序的内部代码。改变这个
tmps = items.get(j+1)
到
tmps = items.get(j)
有关交换的更多信息,请参阅此处 Python Simple Swap Function
第二个问题是set方法。你应该删除这个
temp = Node(newdata)
temp.set_next(current)
if previous is None:
self.head = temp
else:
previous.set_next(temp)
你应该这样写
current.set_data(newData)
(我不知道你是如何实现节点的class)