linked_list_data_structure.py

classNode:
def__init__(self, data=None):
self.data=data
self.next_node=None


classLinkedList:
def__init__(self, head=None):
self.head=head

defisEmpty(self):
returnself.head==None

definsert(self, data):
# create a temp node
temp=Node(data=data)
# point new node to head
temp.next_node=self.head
# set the head as new node
self.head=temp

definsert_after(self, prev, data):
ifprevisNone:
raiseValueError("Given node is not found...")
returnprev

# create a temp node
temp=Node(data=data)
# set next node of temp to the next node of previous
temp.next_node=prev.next_node
# set next node of previous to point temp
prev.next_node=temp

defsize(self):
# start with the head
current=self.head
count=0

# loop unless current is not None
whilecurrent:
count+=1
current=current.next_node
returncount

defsearch(self, data):
# start with the head
current=self.head
found=False

# loop unless current is not None
whilecurrentandnotfound:
# if found, change flag and return data
ifcurrent.data==data:
found=True
else:
# change current to next node
current=current.next_node
ifcurrentisNone:
# raise Exception if not found
raiseValueError("Data is not in the list")
returncurrent

defdelete(self, data):
# start with the head
current=self.head
previous=None
found=False

# loop unless current is not None
whilecurrentandnotfound:
# if found, change flag
ifcurrent.getData() ==data:
found=True
else:
previous=current
current=current.next_node

ifcurrentisNone:
# raise Exception if not found
raiseValueError("Data is not in the list")
ifpreviousisNone:
self.head=current.next_node
else:
previous.next_node=current.next_node