fn main()

Computer is a robot , our program  should identify the repetitive task and make computer do that repetitive task with less lines of code.......

If you are planning to refresh your data structure knowledge, I would recommend this website http://www.geeksforgeeks.org/data-structures/ ...

When I tried to access 'unallocated node value' , as usual 'Segmentation fault' came as output :-) But i am not fully clea...