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Wrap lines that go beyond GitHub Editor (#1925)

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* Wrap lines that go beyond GiHub Editor

* flake8 --count --select=E501 --max-line-length=127

* updating DIRECTORY.md

* Update strassen_matrix_multiplication.py

* fixup! Format Python code with psf/black push

* Update decision_tree.py

Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
This commit is contained in:
Christian Clauss
2020-05-01 23:36:35 +02:00
committed by GitHub
parent bcaa88b26c
commit 6acd7fb5ce
19 changed files with 161 additions and 82 deletions
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15
data_structures/linked_list/doubly_linked_list.py
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@ -1,9 +1,12 @@
"""
- A linked list is similar to an array, it holds values. However, links in a linked list do not have indexes.
- A linked list is similar to an array, it holds values. However, links in a linked
list do not have indexes.
- This is an example of a double ended, doubly linked list.
- Each link references the next link and the previous one.
- A Doubly Linked List (DLL) contains an extra pointer, typically called previous pointer, together with next pointer and data which are there in singly linked list.
- Advantages over SLL - IT can be traversed in both forward and backward direction.,Delete operation is more efficient"""
- A Doubly Linked List (DLL) contains an extra pointer, typically called previous
pointer, together with next pointer and data which are there in singly linked list.
- Advantages over SLL - IT can be traversed in both forward and backward direction.,
Delete operation is more efficient"""
class LinkedList: # making main class named linked list
@ -13,7 +16,7 @@ class LinkedList: # making main class named linked list
def insertHead(self, x):
newLink = Link(x) # Create a new link with a value attached to it
if self.isEmpty() == True: # Set the first element added to be the tail
if self.isEmpty(): # Set the first element added to be the tail
self.tail = newLink
else:
self.head.previous = newLink # newLink <-- currenthead(head)
@ -23,7 +26,9 @@ class LinkedList: # making main class named linked list
def deleteHead(self):
temp = self.head
self.head = self.head.next # oldHead <--> 2ndElement(head)
self.head.previous = None # oldHead --> 2ndElement(head) nothing pointing at it so the old head will be removed
# oldHead --> 2ndElement(head) nothing pointing at it so the old head will be
# removed
self.head.previous = None
if self.head is None:
self.tail = None # if empty linked list
return temp