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Diffstat (limited to 'AoC2023/day11/solver.lisp')
| -rw-r--r-- | AoC2023/day11/solver.lisp | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/AoC2023/day11/solver.lisp b/AoC2023/day11/solver.lisp new file mode 100644 index 0000000..e7feabf --- /dev/null +++ b/AoC2023/day11/solver.lisp @@ -0,0 +1,66 @@ +;; 9:59 +;; 10:31 part1 +;; +(ql:quickload '(fiveam)) +(defparameter eg-input "...#...... +.......#.. +#......... +.......... +......#... +.#........ +.........# +.......... +.......#.. +#...#.....") + +(defun indexes (array) + (loop for v across array + for i from 0 when v collect i)) + +(defun shift (coord spacers) + (count-if (lambda (idx) (< idx coord)) spacers)) + +(defun expanded (point free-rows free-cols) + (destructuring-bind (y x) point + (list (+ y (shift y free-rows)) + (+ x (shift x free-cols))))) + +(fiveam:test parts + (fiveam:is (= 1 (shift 5 '(3 6)))) + (fiveam:is (equal '(7 4) (expanded '(5 3) '(1 2) '(2))))) + +(defun expanded-galaxies (rows) + (let* ((free-rows (make-array (length rows) :initial-element t)) + (free-cols (make-array (length (car rows)) :initial-element t)) + (galaxies (loop for row in rows + for y from 0 + nconc + (loop for col across row + for x from 0 + when (eq col #\#) + collect (list y x) + and do (setf (aref free-rows y) nil + (aref free-cols x) nil))))) + (map 'vector + (lambda (galaxie) + (expanded galaxie + (indexes free-rows) + (indexes free-cols))) + galaxies))) + + +(defun manhattan-dist (s x) + (destructuring-bind ((sx sy) (bx by)) (list s x) + (+ (abs (- bx sx)) (abs (- by sy))))) + + +(defun solver1 (rows) + (loop with gals = (expanded-galaxies rows) + for g across gals + for i from 0 sum + (loop for j from (1+ i) below (length gals) + sum (manhattan-dist g (aref gals j))))) + +(fiveam:test solutions + (fiveam:is (= 374 (solver1 (uiop:split-string eg-input :separator '(#\Newline))))) + (fiveam:is (= 10154062 (solver1 (uiop:read-file-lines "input"))))) |