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我需要爲我的程序添加一個索引和一個計數函數，但是我對如何解決這個問題感到困惑，因爲我的老師非常寬泛。任何想法，我可以做一個索引和計數函數添加到我的鏈接列表？ 這裏是我的代碼：在我的鏈表中添加一個計數和一個索引
from ListNode import ListNode
class LinkedList(object):
#--------------------------------------------------------------
def __init__(self, seq=()):
""" Pre: Creates a Linked List
Post: Creates a list containing the items in the seq=()"""
if seq ==():
# If there is no items to be put into the list, then it creates an empty one.
self.head = None
else:
# Creates a node for the first item.
self.head = ListNode(seq[0], None)
# If there are remaining items, then they're added while keeping track of the last node.
last = self.head
for item in seq[1:]:
last.link = ListNode(item, None)
last = last.link
self.size = len(seq)
#-------------------------------------------------------------
def __len__(self):
'''Pre: Nothing.
Post: Returns the number of items in the list.'''
return self.size
#-------------------------------------------------------------
def _find(self, position):
'''This is a private method, which means it only works in this class.
This returns the last node used. (0 is the first item, size-1 is the last item)
Pre: 0 (less than or equal to) position (less than) self.size
Post: Returns the ListNode at the specified position in the list.'''
assert 0 <= position < self.size
node = self.head
# move forward until we reach the specified node
for i in range(position):
node = node.link
return node
#-------------------------------------------------------------
def append(self,x):
'''This adds (Appends) 'x' onto the end of the list
Post: X is appended to the end of the list.'''
# First create a new node containing x
newNode = ListNode(x)
# This will link it onto the end of the list.
if self.head is not None:
# Not an empty list
node = self._find(self.size - 1)
node.link = newNode
else:
# If it is an empty list.
# You will set self.head to the new node
self.head = newNode
self.size += 1
#-------------------------------------------------------------
def __getitem__(self, position):
''' returns the data item at the location position
Pre: 0 <= position < size
Post: Returns data item at the specified position.'''
node = self._find(position)
return node.item
#-------------------------------------------------------------
def __setitem__(self, position, value):
''' Sets the data item at the location position to the value.
Pre: 0 <= position < self.size
Post: Sets the data item at the specified position to value.'''
node = self._find(position)
node.item = value
#--------------------------------------------------------------
def __delitem__(self, position):
''' Deletes the item at the location position from the list.
Pre: 0 <= position < self.size
Post: The item at the specified position is removed from the list.'''
assert 0 <= position < self.size
self._delete(position)
#--------------------------------------------------------------
def __max__(self):
''' Goes through each node and compares what the max is for the linked list.
Post: Finds the max of the linked list and returns that value.'''
max_value = self.head.item
node = self.head.next
while node is not None:
if node.item > max_value:
max_value = node.item
node = node.link
return max_value
#--------------------------------------------------------------
def __min__(self):
''' Goes through each node and compares what the min is for the linked list.
Post: Finds the min of the linked list and returns that value.'''
min_value = self.head.item
node = self.head.next
while node is not None:
if node.item < min_value:
min_value = node.item
node = node.link
return min_value
#--------------------------------------------------------------
def _delete(self, position):
''' This is a private function where it deletes an item at the location
position from the list.
Pre: 0 <= position < self.size
Post: The item at the specified location is removed from the list.
The item is then returned (To be used with pop.)'''
if position == 0:
# Save the item from the initial node
item = self.head.item
# Change the self.head to point "over" the deleted node.
self.head = self.head.link
else:
# Find the node before the one that you are deleting.
prev_node = self._find(position - 1)
# Save the item from the node you are deleting.
item = prev_node.link.item
# Change the previous node to go over the deleted node. (Example 2 goes to 4)
prev_node.link = prev_node.link.link
self.size -= 1
return item
#--------------------------------------------------------------
def pop(self, i = None):
''' This returns and removes whatever is at position 'i' from the list. It is
defaulted to return and remove the last item.
Pre: self.size > 0 and ((i is None or (0 <= i < self.size))
Post: If I is None, then the last item in the list is removed and then returned.
Otherwise, the item at position 'i' is removed and returned.'''
assert self.size > 0 and (i is None or (0 <= i < self.size))
# The default is to delete the last item in the list.
# 'i' could be zero so we need to compare to None.
if i is None:
i = self.size - 1
return self._delete(i)
#-----------------------------------------------------------------
def insert(self, i, x):
''' Inserts 'x' at the position 'i' is at in the list.
Pre: 0 <= i <= self.size
Post: x is inserted into the list at position 'i', and the old segment
from position 'i' (oldsize-1) are now at position 'i'+1 (newsize - 1).'''
assert 0 <= i <= self.size
if i == 0:
# Inserting before) requires changing/updating self.head.
self.head = ListNode(x, self.head)
else:
# Find the item that this node will be inserted after.
node = self._find(x, self.head)
node.link = ListNode(x, node.link)
self.size += 1
#-----------------------------------------------------------------
def __copy__(self):
''' Post: Returns a new Linked List object that is a shallow copy of self.'''
a = LinkedList()
node = self.head
while node is not None:
a.append(node.item)
node = node.link
return a
#-----------------------------------------------------------------
def __iter__(self):
return LinkedListIterator(self.head)
#---------------------------------------------------------------------
class LinkedListIterator(object):
#-----------------------------------------------------------------
def __init__(self, head):
self.currnode = head
#-----------------------------------------------------------------
def next(self):
if self.currnode is None:
raise StopIteration
else:
item = self.currnode.item
self.currnode = self.currnode.link
return item
這似乎基本爲你們，但我在努力搞清楚什麼我的老師希望我的索引或該計劃數。
你不應該在這裏發表您的實驗室。請問你的助教，講師還是你的朋友？ – taesu 2015-03-02 17:34:03