Assume the board satisfies the representation invariant. Reject completed boards and occupied or out-of-range coordinates; testing membership in the empty component covers both coordinate failures.
finished :: Board -> Bool
finished (os,xs,es) = won os || won xs || null es

play :: Board -> Place -> Board
play b@(os,xs,es) q
  | finished b     = error "play: completed game"
  | q `notElem` es = error "play: unavailable place"
  | length os == length xs = (q:os,xs,rest)
  | otherwise             = (os,q:xs,rest)
  where rest = filter (/=q) es
Here won is defined in part d. Moving one available coordinate into the appropriate occupied component preserves the set partition and the alternating-count rule. Checking completion first preserves the no-moves-after-a-win invariant.

Ancestors (12)

  1. c
  2. 3
  3. Functional programming, design and analysis of algorithms
  4. 2019
  5. Past exam of the year 1 of the computer science course of the University of Oxford
  6. Year 1 of the computer science course of the University of Oxford
  7. Computer science course of the University of Oxford
  8. Undergraduate course of the University of Oxford
  9. Course of the University of Oxford
  10. University of Oxford
  11. List of universities
  12. Home

View article source

Discussion (0)

New discussion

There are no discussions about this article yet.

Articles by others on the same topic (0)

There are currently no matching articles.
See all articles in the same topic Create my own version