diff options
| -rw-r--r-- | aoc/2021/day04/part01.neb | 77 |
1 files changed, 55 insertions, 22 deletions
diff --git a/aoc/2021/day04/part01.neb b/aoc/2021/day04/part01.neb index 49b4a7a..e73a9c5 100644 --- a/aoc/2021/day04/part01.neb +++ b/aoc/2021/day04/part01.neb @@ -44,7 +44,13 @@ (slice lst (+ 1 idx)))) (func has-won-row (row) - (apply and row)) + (reduce + ;(apply and row)) + (lambda (acc x) + (and acc + (int? x))) + row + #true)) (func has-won (board moves) (def checked (check-board board moves)) @@ -69,15 +75,22 @@ (redef winner #true))) winner) - -(func check-board (board moves) - (func check-row (row) - (map - (lambda (x) - (in? x moves)) - row)) - (map check-row board)) +; this could (should?) be interior to check-board +(func check-row (row moves) + (map + (lambda (x) + (if (in? x moves) + 0 ; use an integer + x)) + row)) + +(func check-board (board my-moves) + (map (lambda (x) (check-row x my-moves)) board)) + +; good candidate for stdlib +(func extend (lst1 lst2) + (reduce append lst2 lst1)) ; how do we better iterate through this list? @@ -86,16 +99,36 @@ (def winner #false) (while (not winner) (redef cur (unzip moves (+ 1 (length (first cur))))) - (print (->string cur)) - (print (->string - (map - (lambda (x) (has-won x (first cur))) - boards))) - ;(def checked (check-board (first boards) (first cur))) - ;(print (->string checked)) - (if (nil? (last cur)) - (redef winner #true)) - ) - -(print (->string moves)) -;(print (->string (unzip moves 2))) + + (def win-boards + (drop-while boards + (not (has-won _item_ (first cur))))) + + ; if win-boards is not empty, we found a winner! + (if (not (nil? win-boards)) + (block + (redef winner #true) + + ; result: a 25 element list of ints, where called numbers + ; are a 0, and uncalled numbers are their integer equivalents + (def winning-board + (map + (lambda (x) ; convert all strings to ints + (if (string? x) + (string->int x) + x)) + (reduce extend ; flatten the board from 5x5 to 1x25 + (check-board ; check the board, called numbers become 0 + (first win-boards) + (first cur)) + (list)))) + + (def sum-of-uncalled + (apply + winning-board)) + + ; benefit of zipper -- easy to get recent elements! + (def last-called (string->int (first (first cur)))) + + (print (concat "sum of uncalled: " (->string sum-of-uncalled))) + (print (concat "last called: " (->string last-called))) + (print (concat "answer: " (->string (* sum-of-uncalled last-called))))))) |