程序代写 # Part 1 Hints – cscodehelp代写

# Part 1 Hints

## Length

“`python
def __len__(self):
if self.next == None:
# base case: I’m the only Node! Length must be 1
return 1
else:
# recursive case: total length is the length of next plus 1
return len(self.next) + ????
“`

## Representation

“`python
def __repr__(self):
if self.next == None:
return repr(self.val)
else:
return repr(self.val)+”,”+repr(self.next)
“`

## Indexing

“`python
def __getitem__(self, idx):
if idx == 0:
# base case
return self.????
else:
# recursive case
return self.next[idx-1]
“`

## Negative Indexing

“`python
def __getitem__(self, idx):
if ????: # check if we have a negative index
idx = len(self) + idx

…
“`

## Append

“`python
def append(self, val):
last_node = self
while last_node.next != None:
last_node = last_node.next
last_node.next = Node(????)
““