linkedLists.py

# DONT CHANGE THIS CODE
# (UNLESS YOU NEED TO DO SPECIFIC MODIFICATIONS TO THE FUNCTIONS)


# Insert a node in a given Singly Linked List (recursively)
class Node:
    # Structure of the node.
    def __init__(self, val):
        self.val = val
        self.next = None


# Insert a node at first position in the given Linked List
def insertAtFirst(listHead, val):
    new = Node(val)
    new.next = listHead
    return new
# Time Complexity - O(1)


# Insert a node at the end of the given Linked List (recursively)
def insertAtEnd(listHead, val):
    if listHead is None:
        new = Node(val)
        return new

    if listHead.next is None:
        new = Node(val)
        listHead.next = new
        return listHead

    insertAtEnd(listHead.next, val)
    return listHead
# Time Complexity - O(n)


# Insert a node at a specific position in the given Linked List (recursively)
def insertInBetween(temp, val, pos):

    # if head is None and given position is greater than 0
    if temp is None and pos>0:
        return temp

    # if the node is to be added at first position
    if pos == 0:
        new = Node(val)
        new.next = temp
        return new

    # if the node is to be added at second position
    if pos == 1:
        new = Node(val)
        new.ext = temp.next
        temp.next = new
        return temp

    insertInBetween(temp.next, val, pos-1)
    return temp
# Time Complexity - O(i)


# Function to print the Linked List through Recursion
def printll(head):
    if head == None:
        return
    print(head.val, end='  ->  ')
    printll(head.next)
# Time Complexity - O(n)
# where n is the length of the linked list


if __name__ == '__main__':
    pass


'''Implemented and adapted by Alejandro Ríos (GitHub: @alejoriosm04)'''