我正在尝试编写插入函数。这是我到目前为止，但它只输出[15]。我主要与插入函数中if和elif语句中的节点所引用的内容相混淆。
class Container:
class node:
def __init__( self, value, nextNode, prevNode ):
self.value = value
self.next = nextNode
self.prev = prevNode
def __init__( self ):
self.top = self.last = None
self.size = 0
def __len__( self ):
return self.size
def _locate( self, val ):
currentNode=self.top
while True:
if currentNode is None:
return None, False
# code the rest of _locate. Make a complete case analysis
elif currentNode.value == val:
return currentNode, True
elif currentNode.value>val:
return currentNode, False
elif currentNode.next == None:
return None, False
else:
currentNode = currentNode.next
#Code the three functions
def find( self, val ):
temp = val
if self._locate(temp) is True:
return True
else:
return False
def insert( self, val ):
#use _locate. If found=True, do nothing
# If found=False and node is not None,
# then insert a new node just before the returned node
# If found=False and node is None
# then insert a new node at the last pointer
# And change size
# Complete the function code in the four cases below
node, found = self._locate(val)
if found==False:
newNode = self.node(val, None, None)
if node is not None and node.prev is not None:
newNode.next = newNode
elif node is not None and node.prev is None:
newNode.next = newNode
elif node is None and self.last is not None:
self.prev = self.top
selt.top = self.top.next
elif node is None and self.last is None:
self.top = newNode
def delete( self, val ):
# Use _locate again.
# Delete the returned node if found is True
# in the four cases below
node, found = self._locate(val)
'''
if found:
if node.prev is not None and node.next is not None:
node.prev = node.next #trying to connect node.prev pointer to node.next pointer
elif node.prev is not None and node.next is None:
self.last = node.prev #make the previous node the last node
elif node.prev is None and node.next is not None:
self.top = node.next #current node is first node, change it so next node is the new first node
elif node.prev is None and node.next is None:
self.size = 0 #there's only one node in list, change the size so now there's zero
'''
#For code check
c = Container()
c.insert(10)
c.insert(4)
c.insert(2)
c.insert(15)
c.delete(4)
c.insert(8)
c.insert(9)
c.delete(10)
check=[]
pointer = c.top
while pointer is not None:
check.append(pointer.value)
pointer = pointer.next
print(check)
print(c.find(8), c.find(10))
# The output should be
# [2, 8, 9, 15]
# True False
答案 0 :(得分：0)
正如@chepner所提到的，您的查找功能会调用“定位”来查找＆＃39;返回一个元组，但是你将这个元组与一个值（即True或False）进行比较
class Container_insert_notSorted:
class node:
def __init__( self, value, nextNode, prevNode ):
self.value = value
self.next = nextNode
self.prev = prevNode
def __init__( self ):
self.top = self.last = None
self.size = 0
def __len__( self ):
return self.size
def _locate( self, val ):
currentNode=self.top
while True:
if currentNode is None:
return None, False
elif currentNode.value == val:
return currentNode, True
elif currentNode.next == None:
return None, False
else:
currentNode = currentNode.next
return None, False
#Code the three functions
def find( self, val ):
node, found = self._locate(val)
return found
def insert( self, val ):
newNode = self.node(val, None, None)
if self.last is None:
self.top = newNode
self.last = newNode
else:
node, found = self._locate(self.last.value)
if found:
newNode.prev = node.value
node.next = newNode
self.last = newNode
逻辑是
后续运行