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+--- Thread: Deleting the first item in linked list (/thread-16569.html)
Deleting the first item in linked list - dan789 - Mar-05-2019
Hello, this is what I have so far:
class Linked_list:
def __init__(self, data, next=None):
self.data, self.next = data, next
def print_list(list):
while list is not None:
print(list.data, end=' ---> ')
list = list.next
print(None)
def make(sequence):
list = None
for value in reversed(sequence):
list = Linked_list(value, list)
return list
def remove_first(list):
...I simply don´t know how to delete the first item of my linked list. I should use just structure I wrote above. Can you give me a help?Thanks.
RE: Deleting the first item in linked list - ichabod801 - Mar-05-2019
Using list as a variable name is a bad idea. list is a built-in, and by using it as a variable name, you block the use of the built-in, which could cause errors in other code.
Let's say your linked list is called llist. llist is actually the first item in you list, and it links to the next item in the list. The second item in the list is llist.next. Can you see then how to make the first item in your list be the second item in your list, thus deleting the previous first item?
RE: Deleting the first item in linked list - dan789 - Mar-05-2019
I could change a refference to the second item? But not sure how to do this using a separate function remove_first.
RE: Deleting the first item in linked list - ichabod801 - Mar-05-2019
If remove_first is not supposed to have a return value, you could copy the values of the second item in the list into the first item of the list.
RE: Deleting the first item in linked list - dan789 - Mar-05-2019
Something like this?
llist.data = llist.next.data
RE: Deleting the first item in linked list - ichabod801 - Mar-05-2019
That's half of it.
RE: Deleting the first item in linked list - dan789 - Mar-05-2019
llist.next = llist.next.next works at least in my case. Is it correct?
RE: Deleting the first item in linked list - ichabod801 - Mar-05-2019
Yeah, that's the other half.