Puzzle #32: Rearranging books
30 November 2019
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From New Scientist #3258, 30th November 2019 [link] [link]
Once a week, it is Jordie’s job at the library to put books back in order on the shelves.
This week, he finds that the 10-volume encyclopedia has been mixed up in the order shown above. He has to put them back in order, and since the books are heavy, he wants to move as few volumes as possible.
A move consists of taking a book off the shelf and sliding the other books to the side to make space, if necessary. What is the smallest number of moves he needs to make to rearrange the books in the order 1 to 10 from left to right?