Story about writing a novel already written [duplicate]

Question

A long time ago I read about a novel, short story or possibly a movie (I can't remember what it was exactly, most likely a novel though) telling the story of a man who writes a book only to later discover that someone else has already written the exact book, word-by-word, possibly years before.

I don't remember how the mystery is solved - if you know what story this is, please don't tell me how it ends.

Edit to rest the duplicate hunters: there was nothing about any time machine in my recollections. I have already selected an answer. And I did say that I don't want to know how this story ends.

Answer 1

This could be "Who's Cribbing" by Jack Lewis, which can be read here.

It's written as a series of letters between a prospective writer and a publisher, and starts thus:

Mr. Jack Lewis 90-26 219 St. Queens Village, N.Y.

Dear Mr. Lewis:

We are returning your manuscript "The Ninth Dimension." At first glance, I had figured it a story well worthy of publication. Why wouldn't I? So did the editors of Comic Tales back in 1934 when the story was first published. As you no doubt know, it was the great Todd Thromberry who wrote the story you tried to pass off on us as an original. Let me give you a word of caution concerning the penalties resulting from plagiarism.

         Sincerely,
          Doyle P. Gates
          Science Fiction Editor
          Deep Space Magazine

Lewis then complains that he's never heard of Thromberry, but the editor explains that it's a word-for-word copy:

By "copy," I do not mean rewrite word for word one or more of his works, as you have done. For while you state this has been accidental, surely you must realize that the chance of this phenomenon actually happening is about a million times as great as the occurrence of four pat royal flushes on one deal.

However, it should be noted that this itself is an idea that has occurred, with variations, a number of times. Arthur C. Clarke, for example, wrote "The Longest Science Fiction Story Ever Told" (actually quite short, but 'longest' because it's recursive and infinite) in which the story being plagiarized is the editor's letter about how the story has already been done.

Answer 2

Could it be Hindsight by Harry Turtledove? Published in 1984 in Analog magazine. Does your memory include a female time traveler, rock music, a dot-matrix printer, Apollo 13, and the Tet Offensive?

From the wiki:

The story, which takes place in Los Angeles in 1953, involves a science fiction author and a magazine editor who become suspicious of another author, Mark Gordian, who seems to be plagiarizing others work and writing eerily prescient fiction. Upon closer examination, it is revealed that Mark Gordian is actually Michelle Gordian, a time traveler from 1983 who has attempted to change her cynical future, dominated by the disappointments of Watergate and Vietnam.

Also from the wiki:

Her writing eventually drew the unwanted attention of Pete Lundquist, another science fiction author who was convinced that "Mark's" story, "Reactions" was plagiarized from an as-of-yet published Lundquist work. He and editor Jim McGregor headed for Gardena to confront Gordian. Both were surprised to learn that Gordian was a woman. However, Lundquist surprised Gordian when he deduced she was a time-traveler.

Answer 3

Perhaps you mean the novella Secret Window, Secret Garden by Stephen King, published in 1990 in the collection "Four past Midnight". The plot description on Wikipedia starts with:

Mort Rainey is a successful novelist in Maine. One day, he is confronted by a man from Mississippi named John Shooter who claims Mort plagiarized a story he wrote. Mort vehemently denies ever plagiarizing anything. Shooter leaves, but not before leaving his manuscript, "Secret Window, Secret Garden". Mort notices that Shooter left without his story then drops it in the trash can. When Mort's housemaid recovers the manuscript—thinking it belongs to Mort—he finally reads Shooter's story, discovering that it is almost identical to his short story "Sowing Season". The two differ but only slightly in that they share the same plot elements. The only differences are the title, the character's name, the diction, and the ending. Mort becomes disturbed by these findings.

Please note that the two stories are only "almost identical", but otherwise this seems to be a good match.