Question

def array_to_list(data):

    '''

    Converts an array to linked list with the same order as in array

    returns None if array is empty

    '''

    head = None

    # for each value in array

    for val in data:

        # if list is empty then create a new head node

        if head is None:

            head = list_node.ListNode(val)

            temp = head

        # else create a new node and add it to the list

        else:

            temp.next = list_node.ListNode(val)

            temp = temp.next

    return head

def pair(list1, list2):

    '''

    Retruns a list with each node storing tuple of value pairs from the given lists

    The returned list is of the length same as the smaller of the two lists givens

    '''

    if list1 is None or list2 is None:

        return None

    head = list_node.ListNode((list1.val,list2.val))

    temp, temp1, temp2 = head, list1.next, list2.next

    while temp1 is not None and temp2 is not None:

        temp.next = list_node.ListNode((temp1.val,temp2.val))

        temp, temp1, temp2 = temp.next, temp1.next, temp2.next

    temp.next = None

    return head

change these functions in a recursively way.

and please add some comments like this

"""

A summary/description of what the function does.

Parameters: give a brief description for each parameter (if there are any)

Returns: give a brief description of each of the return values (if there are any)

Pre-condition: detail any assumptions made by the function, i.e., any pre-condition that must be met in order for the function to work correctly

Post-condition: detail what we can expect to be true after the function has finished execution, i.e., its post-condition

""

Answer 1

def array_to_list(data,index = 0):

    '''
    Converts an array to linked list with the same order as in array
    returns None if array is empty
    '''
    if len(data) == index:
        return None
    temp = list_node.ListNode(data[index])
    temp.next = array_to_list(data, index=index+1)
    return temp





def pair(list1, list2,index1 = 0,index2 = 0):
    '''
    Retruns a list reccusively with each node storing tuple of value pairs from the given lists
    The returned list is of the length same as the smaller of the two lists givens
    '''
    if index1 == len(list1) or index2 == len(list2):
        return None
    temp = list_node.ListNode((list1[index1], list2[index2]))
    temp.next = pair(list1, list2,index1 = index1 + 1, index2 = index2+1)
    return temp