Question

Python Program Only:

Write the function definition only of the "get(self, index)" function.

Plug your method in the code file shared with you and test it in the main to get the element at index 3 of mylist2 .

class Node:
    def __init__(self, e):
        self.element = e
        self.next = None

class LinkedList:
    def __init__(self):
        self.head = None
        self.tail = None
        self.size = 0

    def addFirst(self, e):
        newNode = Node(e)
        newNode.next = self.head
        self.head = newNode
        self.size = self.size + 1


    def addLast(self, e):
        newNode = Node(e)
        if self.tail == None:
            self.head = self.tail = newNode
        else:
            self.tail.next = newNode
            self.tail = self.tail.next
        self.size += 1

    def add(self, e):
        self.addLast(e)

    def insert(self, index, e):
        newNode = Node(e)
        if index == 0:
            self.addFirst(e)
        elif index >= self.size:
            self.addLast(e)
        else:
            current = self.head
            for i in range (1, index):
                current = current.next
            temp = current.next
            current.next = newNode
            (current.next).next = temp
            self.size += 1

    def removeFirst(self):
        if self.size == 0:
            return None
        else:
            temp = self.head
            self.head = self.head.next
            self.size -= 1
            if self.head == None:
                self.tail = None
            return temp.element

    def removeLast(self):
        if self.size == 0:
            return None
        elif self.size == 1:
            temp = self.head
            self.head = self.tail = None
            self.size = 0
            return temp.element
        else:
            current = self.head

            for i in range(self.size - 2):
                current = current.next

            temp = self.tail
            self.tail = current
            self.tail.next = None
            self.size -= 1
            return temp.element

    def removeAt(self, index):
        if index < 0 or index >= self.size:
            return None
        elif index == 0:
            return self.removeFirst()
        elif index == self.size - 1:
            return self.removeLast()
        else:
            previous = self.head

            for i in range(1, index):
                previous = previous.next

            current = previous.next
            previous.next = current.next
            self.size -= 1
            return current.element

    def getFirst(self):
        if self.size == 0:
            return None
        else:
            return self.head.element

    def getLast(self):
        if self.size == 0:
            return None
        else:
            return self.tail.element

    def indexOf(self, e):

        current = self.head
        i = 0

        while current != None:
            if current.element == e:
                return i
            i += 1
            current = current.next

        return -1

    def clear(self):
        self.head = None
        self.tail = None
        self.size = 0

    def contains(self, e):
        if self.indexOf(e) >= 0:
            return True
        else:
            return False


    def remove(self,e):
        index = self.indexOf(e)
        if index == -1:
            return False
        else:
            self.removeAt(index)
        return True

    def toString(self):
        result = "["

        current = self.head
        for i in range(self.size):
            result += str(current.element)
            current = current.next
            if current != None:
                result += ", "
            else:
                result += "]"

        return result

    def set(self, index, e):
        if index < 0 or index >= self.size:
            print("Index is out of range")
            return None

        current = self.head
        for i in range(index):
            current = current.next

        current.element = e

    def isEmpty(self):
        if self.size == 0:
            return True
        else:
            return False

    def getSize(self):
        return self.size

    def get(self, index): ##############I need to add this and then print it in the main function######
        return


def main():

    mylist1 = LinkedList()
    numOfElements = int(input("How many elements you want to add "))

    for i in range(numOfElements):
        print("Enter Element ", i+1," ")
        element = input()
        mylist1.add(element)

    print("Linked List mylist1 is as follows ", mylist1.toString())
    print("\n \n")


    mylist2 = LinkedList()
    listElements = input("Enter the elements you need to add seperated by white space \n")

    lista = listElements.split()


    print("Lista = ", lista, "\n")


    for e in lista:
        mylist2.add(e)

    print("Linked List mylist2 is as follows: ", mylist2.toString(), "\n")
    print("mylist2.indexOf('Detroit') is", mylist2.indexOf("Detroit"))


    print("My linked list is as follows: ",mylist2.toString())


    mylist2.remove("Dallas")
    print("Linked List after removing Dallas: ", mylist2.toString())


    mylist2.set(1,"Chicago")
    print("Linked List after setting element: ", mylist2.toString())


    if mylist2.contains("Erie"):
        print("Erie is found")
    else:
        print("Erie is not in the list")

    print("Element at index 3 of mylist 2 is: ", self.index(3)) ######## my attempt ####
main()

Answer 1

Given below is the completed code for the question. PLEASE MAKE SURE INDENTATION IS EXACTLY AS SHOWN IN IMAGE.
Please do rate the answer if it helped. Thank you.

class Node:
   def __init__(self, e):
       self.element = e
       self.next = None

class LinkedList:
   def __init__(self):
       self.head = None
       self.tail = None
       self.size = 0

   def addFirst(self, e):
       newNode = Node(e)
       newNode.next = self.head
       self.head = newNode
       self.size = self.size + 1

   def addLast(self, e):
       newNode = Node(e)
       if self.tail == None:
           self.head = self.tail = newNode
       else:
           self.tail.next = newNode
           self.tail = self.tail.next
       self.size += 1

   def add(self, e):
       self.addLast(e)

   def insert(self, index, e):
       newNode = Node(e)
       if index == 0:
           self.addFirst(e)
       elif index >= self.size:
           self.addLast(e)
       else:
           current = self.head
           for i in range (1, index):
               current = current.next
           temp = current.next
           current.next = newNode
           (current.next).next = temp
           self.size += 1

   def removeFirst(self):
       if self.size == 0:
           return None
       else:
           temp = self.head
           self.head = self.head.next
           self.size -= 1
           if self.head == None:
               self.tail = None
           return temp.element

   def removeLast(self):
       if self.size == 0:
           return None
       elif self.size == 1:
           temp = self.head
           self.head = self.tail = None
           self.size = 0
           return temp.element
       else:
           current = self.head

           for i in range(self.size - 2):
               current = current.next

           temp = self.tail
           self.tail = current
           self.tail.next = None
           self.size -= 1
           return temp.element

   def removeAt(self, index):
       if index < 0 or index >= self.size:
           return None
       elif index == 0:
           return self.removeFirst()
       elif index == self.size - 1:
           return self.removeLast()
       else:
           previous = self.head

           for i in range(1, index):
               previous = previous.next

           current = previous.next
           previous.next = current.next
           self.size -= 1
           return current.element

   def getFirst(self):
       if self.size == 0:
           return None
       else:
           return self.head.element

   def getLast(self):
       if self.size == 0:
           return None
       else:
           return self.tail.element

   def indexOf(self, e):

       current = self.head
       i = 0

       while current != None:
           if current.element == e:
               return i
           i += 1
           current = current.next

       return -1

   def clear(self):
       self.head = None
       self.tail = None
       self.size = 0

   def contains(self, e):
       if self.indexOf(e) >= 0:
           return True
       else:
           return False

   def remove(self,e):
       index = self.indexOf(e)
       if index == -1:
           return False
       else:
           self.removeAt(index)
       return True

   def toString(self):
       result = "["

       current = self.head
       for i in range(self.size):
           result += str(current.element)
           current = current.next
           if current != None:
               result += ", "
           else:
               result += "]"

       return result

   def set(self, index, e):
       if index < 0 or index >= self.size:
           print("Index is out of range")
           return None

       current = self.head
       for i in range(index):
           current = current.next

       current.element = e

   def isEmpty(self):
       if self.size == 0:
           return True
       else:
           return False

   def getSize(self):
       return self.size

   def get(self, index):
       if index < 0 or index >= self.size:
           return None
      
       current = self.head
       for i in range(index):
           current = current.next
       return current.element

def main():

   mylist1 = LinkedList()
   numOfElements = int(input("How many elements you want to add "))

   for i in range(numOfElements):
       print("Enter Element ", i+1," ")
       element = input()
       mylist1.add(element)

   print("Linked List mylist1 is as follows ", mylist1.toString())
   print("\n \n")

   mylist2 = LinkedList()
   listElements = input("Enter the elements you need to add seperated by white space \n")

   lista = listElements.split()

   print("Lista = ", lista, "\n")

   for e in lista:
       mylist2.add(e)

   print("Linked List mylist2 is as follows: ", mylist2.toString(), "\n")
   print("mylist2.indexOf('Detroit') is", mylist2.indexOf("Detroit"))

   print("My linked list is as follows: ",mylist2.toString())

   mylist2.remove("Dallas")
   print("Linked List after removing Dallas: ", mylist2.toString())

   mylist2.set(1,"Chicago")
   print("Linked List after setting element: ", mylist2.toString())

   if mylist2.contains("Erie"):
       print("Erie is found")
   else:
       print("Erie is not in the list")

   print("Element at index 3 of mylist 2 is: ", mylist2.get(3))
main()