use python: singly linked list class 1. Re-implement the remove method so that i

Question

use python: singly linked list class

1. Re-implement the remove method so that it works correctly in the case where the item is not in the list

Code

class Node:
def __init__(self,initdata):
self.data = initdata
self.next = None

def getData(self):
return self.data

def getNext(self):
return self.next

def setData(self,newdata):
self.data = newdata

def setNext(self,newnext):
self.next = newnext

class UnorderedList:

def __init__(self):
self.head = None

def isEmpty(self):
return self.head == None

def add(self,item):
temp = Node(item)
temp.setNext(self.head)
self.head = temp

def size(self):
current = self.head
count = 0
while current != None:
count = count + 1
current = current.getNext()

return count

def search(self,item):
current = self.head
found = False
while current != None and not found:
if current.getData() == item:
found = True
else:
current = current.getNext()

return found

def remove(self,item):
current = self.head
previous = None
found = False
while not found:
if current.getData() == item:
found = True
else:
previous = current
current = current.getNext()

if previous == None:
self.head = current.getNext()
else:
previous.setNext(current.getNext())

Explanation / Answer

PROGRAM CODE:

# your code goes here
class Node:
   def __init__(self,initdata):
       self.data = initdata
       self.next = None
   def getData(self):
       return self.data
   def getNext(self):
       return self.next
   def setData(self,newdata):
       self.data = newdata
   def setNext(self,newnext):
       self.next = newnext

class UnorderedList:
   def __init__(self):
       self.head = None
   def isEmpty(self):
       return self.head == None
   def add(self,item):
       temp = Node(item)
       temp.setNext(self.head)
       self.head = temp
   def size(self):
       current = self.head
       count = 0
       while current != None:
           count = count + 1
           current = current.getNext()
       return count
   def search(self,item):
       current = self.head
       found = False
       while current != None and not found:
           if current.getData() == item:
               found = True
           else:
               current = current.getNext()
       return found
   def remove(self,item):
       current = self.head
       previous = None
       found = False
       while not found:
           if current.getData() == item:
               found = True
               if current.getNext() != None:
                   current.setData(current.getNext().getData())
                   current.setNext(current.getNext().getNext())
               else:
                   previous.setNext(None);
           else:
               previous = current
               current = current.getNext()
               if current == None:
                   found = True;

#main function running here
input = UnorderedList();
input.add(2);
input.add(4);
print(input.size()) # output is 2
input.remove(2);
print(input.size()) # output is 1
input.add(6);
input.add(3);
print(input.size()) # output is 3
input.remove(2); # 2 is already removed
print(input.size()) # output is 3

OUTPUT:

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