System Engineer Specialist

1. I created an array where registration details will be stored. This contains Phone number as the unique field for every participant.
2. If a user selects register, I collect user details and phone number, then I checked if the phone number exists in my array or not. If yes, I redirect the user to "login page" saying the "user has already registered". If no, I would process the registration and add the details in my array
3. If a user selects login, I collect phone number and password, then I checked if the phone number exists in my array or not. If yes, I I would redirect the user to "Home" Page. If no, I would ask them to register first.

Traverse the list and find the length M.
Again traverse the linked list from the start till we reach the (M − N)th node.
Now we delete the (M - N + 1)th node and return the head pointer. Before deleting the node, we need to relink the next pointer of the (M - N)th node to the (M − N + 2)th node.