Question

in phyton please.

b. Given a singly linked list, Your task is to remove every K-th node of the linked list. Assume that K is always less than or equal to length of Linked List. Examples : Input : 1->2->3->4->5->6->7->8 k = 3 Output : 1->2->4->5->7->8 As 3 is the k-th node after its deletion list would be 1->2->4->5->6->7->8 And now 4 is the starting node then from it, 6 would be the k-th node. So no other kth node could be there. So, final list is: 1->2->4->5->7->8. Input: 1->2->3->4->5->6 k = 1 Output: Empty list All nodes need to be deleted

Answer 1

"""

Program to remove kth node.

Python version:3.6.1

"""

class Node:

    """

    A node in a linked list

    """

    def __init__(self, value):

        self.value = value

        self.next = None

def print_list(head:Node):

    list_str = ""

    if head is None:

        print("Empty List")

    while head is not None:

        list_str = f"{list_str}{head.value}"

        if head.next is not None:

            list_str = f"{list_str}->"

        

        head = head.next

    

    print(list_str)

def remove_kth_nodes(head:Node, k:int):

    """

    modifies the head node to remove every kth node, and returns the new list

    """

    # A check to verify if k less than the length of the linked list

    # is not needed since it has been clearly mentioned that k is always less

    # k == 0 is invalid

    if k == 0:

        raise Exception("k cannot be 0")

    # k == 1 means first node

    if k == 1:

        return None

    # find every k - 1 th node and remove it

    current = head

    

    # Start from first node, therefore i = 1

    i = 1

    while current is not None:

        if i == k-1:

            # remove the next node, if it is not none

            if current.next is not None:

                current.next = current.next.next

            current = current.next

            i = 1

        else:

            # skip the next node

            current = current.next

            i += 1

    return head

    

if __name__ == "__main__":

    n = Node(1)

    n.next = Node(2)

    n.next.next = Node(3)

    n.next.next.next = Node(4)  

    n.next.next.next.next = Node(5)

    n.next.next.next.next.next = Node(6)

    n.next.next.next.next.next.next = Node(7)

    n.next.next.next.next.next.next.next = Node(8)

    print_list(n)

    n = remove_kth_nodes(n, 3)

    print_list(n)