ctci 2.1

Basic linkedlist from scratch and duplicate check using hashmap
ctci 2.2

Using two pointers in linear time
ctci 2.3

Deleting current node by copying next data to itself
ctci 2.4

Temp nodes in two lists and merging them
ctci 2.5

trivial addition operation
ctci 2.6

Using fast pointer and slow pointer
ctci 2.7

Divide into separate linked lists and comparing individual lists