Answer to Question #47705 in C for lokkanithya

Question

There is a mail id [e-mail]. John owns this id and he has his friends contact under the group name Rockers. Now he lost many of his friends mail id from his group. It was deleted accidentally. So he asks his friends(2000 friends) in face book to add their name in the newly opened mail id [e-mail] so that he could import the contacts to his mail id, [e-mail]. While importing he finds that if a friend's mail id is already there in his mail id(keep in mind that although many mail ids are lost,still some of them are there), the mail id is seen double times(already present+new) there at [e-mail]. He doesn't know how to proceed. He can solve it if he has a C program which provides the output in such a way that it displays only the friends mail id that are not already there in his mail id. Write a C program.