You will be writing helper methods for the LinkedList class that we developed and testing them.

For this task, assume that the data that you are handling are integers.  You may not change the signature of any of these functions. But you may add as many helper functions as needed.

Implement the following methods. 

# Get number of links of a singly Linked List.

# "Input: [1, 2, 3, 4, 5, 6]"

# "Expected: 6"

def get_num_links (self):

 

# Add an item at the beginning of the list

def insert_first (self, data):

 

# Add an item at the end of a list

def insert_last (self, data):

 

# Add an item in an ordered list in ascending order

# Assume that the list is already sorted

def insert_in_order (self, data):

 

# Search in an unordered list, return the link if found, None if not found

def find_unordered (self, data):

 

# Search in an ordered list, return the link if found, return None if not found

def find_ordered (self, data):

Please use and finish the following code template:

import random
 

class Link (object):

    # constructor

    def __init__ (self, data, next = None):

        self.data = data

        self.next = next

 

class LinkedList (object):

    # make a linked list

    # you may add other attributes

    def __init__ (self):

        self.first = None
 

    # Get number of links of a singly Linked List.

    # "Input: [1, 2, 3, 4, 5, 6]"

    # "Expected: 6"

    # TODO!

    def get_num_links (self):

        ...

 

    # Add an item at the beginning of the list

    def insert_first (self, data):
 

    # add an item at the end of a list

    def insert_last (self, data):
 

    # Add an item in an ordered list in ascending order

    # Assume that the list is already sorted

    def insert_in_order (self, data):

 

    # Search in an unordered list, return None if not found

    def find_unordered (self, data):
 

    # Search in an ordered list, return None if not found

    def find_ordered (self, data):

 

    # String representation of data 10 items to a line, 2 spaces between data

    def __str__ (self):

        string = ""

        count = 0

        curr = self.first

        if curr == None:

            return string

 

        while curr.next != None:

            string += str(curr.data)

            count += 1

            if count != 10:

                string += "  "

            else:

                string += ""

                count = 0

            curr = curr.next

        string += str(curr.data)

        return string

 

# This main function is just for visualization and tests.

 

def main():

    # Test methods insert_first() and __str__() by adding more than

    # 10 items to a list and printing it.

    linked_List = LinkedList()

    for i in range(9, -1, -1):

        linked_List.insert_first(i)

    print(linked_List)

 

    # Test method insert_last()

    linked_List.insert_last(10)

    print(linked_List)

 

    # Test method insert_in_order()

    linked_List.insert_in_order(5)

    print(linked_List)
 

    # Test method get_num_links()

    num_links = linked_List.get_num_links()

    print(num_links)
 

    # Test method find_unordered()

    # Consider two cases - data is there, data is not there

    print(linked_List.find_unordered(3))

    print(linked_List.find_unordered(11))

 

    # Test method find_ordered()

    # Consider two cases - data is there, data is not there

    print(linked_List.find_ordered(6))

    print(linked_List.find_ordered(12))
 

if __name__ == "__main__":

    main()