Linked Lists-Insert a node at a specific position in a linked list.py

#Problem Link : https://www.hackerrank.com/challenges/insert-a-node-at-a-specific-position-in-a-linked-list/problem?isFullScreen=true&h_l=interview&playlist_slugs%5B%5D=interview-preparation-kit&playlist_slugs%5B%5D=linked-lists

#Ans:

#!/bin/python3

import math
import os
import random
import re
import sys

class SinglyLinkedListNode:
    def __init__(self, node_data):
        self.data = node_data
        self.next = None

class SinglyLinkedList:
    def __init__(self):
        self.head = None
        self.tail = None

    def insert_node(self, node_data):
        node = SinglyLinkedListNode(node_data)

        if not self.head:
            self.head = node
        else:
            self.tail.next = node


        self.tail = node

def print_singly_linked_list(node, sep, fptr):
    while node:
        fptr.write(str(node.data))

        node = node.next

        if node:
            fptr.write(sep)

#
# Complete the 'insertNodeAtPosition' function below.
#
# The function is expected to return an INTEGER_SINGLY_LINKED_LIST.
# The function accepts following parameters:
#  1. INTEGER_SINGLY_LINKED_LIST llist
#  2. INTEGER data
#  3. INTEGER position
#

#
# For your reference:
#
# SinglyLinkedListNode:
#     int data
#     SinglyLinkedListNode next
#
#


class SinglyLinkedListNode:
    def __init__(self, node_data):
        self.data = node_data
        self.next = None


class SinglyLinkedList:
    def __init__(self):
        self.head = None
        self.tail = None

    def insert_node(self, node_data):
        node = SinglyLinkedListNode(node_data)

        if not self.head:
            self.head = node
        else:
            self.tail.next = node

        self.tail = node


def print_singly_linked_list(node, sep, fptr):
    while node:
        fptr.write(str(node.data))

        node = node.next

        if node:
            fptr.write(sep)


# Complete the insertNodeAtPosition function below.

#
# For your reference:
#
# SinglyLinkedListNode:
#     int data
#     SinglyLinkedListNode next
#
#
def insertNodeAtPosition(head, data, position):
    prev = head
    while position > 1:
        prev = prev.next
        position -= 1

    node = SinglyLinkedListNode(data)
    node.next = prev.next
    prev.next = node

    return head



if __name__ == '__main__':