Question

In python I want to create a singular function that takes two parameters 'head; and 'skip'.

Head is a linked list. Skip is a non negative value. If skip is zero it should return the linked list unchanged. The skip amount determines the amount to skip over. I want to change the linked list accordingly and then return the linked list with the modifications, not a list.

If you have a linked list 11 -> 12 -> 18 -> 20 -> 24 -> 32 -> 38 -> 44

and skip =2, then the linked list you return should be the following:

18 -> 32

If skip = 1, then the linked list you return should be the following:

12 -> 20 -> 32 -> 44

Answer 1

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

class LinkedList: 

        def __init__(self): 
                self.head = None

        def push(self, new_data): 
                new_node = Node(new_data) 
                new_node.next = self.head 
                self.head = new_node 

        
        def getNth(self, index): 
                current = self.head # Initialise temp 
                count = 0 # Index of current node 

                while (current): 
                        if (count == index): 
                                return current.data 
                        count += 1
                        current = current.next

                assert(false) 
                return 0; 


if __name__=='__main__': 

        llist = LinkedList() 

        print("length of linked list")
        length = int(input())
        print("enter data for linked list")
        for _ in range(length):
                llist.push(int(input())); 

        print('skips:')
        skip = int(input())+1

        indexes = list(range(0,length,skip))
        indexes.pop(0)
        
        for n in reversed(indexes):
                print(llist.getNth(n-1),"->",end='') 
        print("completed")

Approach:

1. We create a linkedlist taking input
2. We create a second list with indexes that need to be printed
3. We print each of those indexes in reverse order to get the required list.

Alternatively, you can save this newly created linkedlist by simply creating a new object and pushing the data there.