diff options
Diffstat (limited to 'puzzle-3.lisp')
-rw-r--r-- | puzzle-3.lisp | 67 |
1 files changed, 0 insertions, 67 deletions
diff --git a/puzzle-3.lisp b/puzzle-3.lisp deleted file mode 100644 index dcb8bc3..0000000 --- a/puzzle-3.lisp +++ /dev/null @@ -1,67 +0,0 @@ -(defvar input (uiop:read-file-string "puzzle-3-input.txt")) - -(defun split-string-in-two (s) - (let ((len (length s))) - (list (subseq s 0 (/ len 2)) (subseq s (/ len 2))))) - -(defvar inputs (with-input-from-string (s input) - (loop - for line = (read-line s nil) - until (null line) - collect (split-string-in-two line)))) - -(defun string-to-clist (str) - (loop for char across str collect char)) - -(defun common-types (s1 s2) - (car (intersection - (string-to-clist s1) - (string-to-clist s2)))) - -(defvar shared (mapcar (lambda (x) - (destructuring-bind (s1 s2) x - (common-types s1 s2))) - inputs)) - -(defun priority-map (c) - (if (upper-case-p c) - (+ 27 (- (char-code c) (char-code #\A))) - (+ 1 (- (char-code c) (char-code #\a))))) - -(defvar round-1-answer (reduce #'+ (mapcar #'priority-map shared))) - -;; Round 2 - -;; Simple recursive algorithm which produces consecutive groups of 3 elements -(defun group-by-3 (lst) - (if (null lst) - nil - (cons - (list (car lst) (car (cdr lst)) (car (cdr (cdr lst)))) - (group-by-3 (cdr (cdr (cdr lst))))))) - -;; Note the use of group-by-3 here -(defvar inputs (group-by-3 - (with-input-from-string (s input) - (loop - for line = (read-line s nil) - until (null line) - collect line)))) - -;; Extend intersection to three -(defun common-types-3 (s1 s2 s3) - (car - (intersection - (string-to-clist s1) - (intersection - (string-to-clist s2) - (string-to-clist s3))))) - -;; Extend the destructuring bind and use of common-types-3 -(defvar shared (mapcar (lambda (x) - (destructuring-bind (s1 s2 s3) x - (common-types-3 s1 s2 s3))) - inputs)) - -;; Same as before -(defvar round-2-answer (reduce #'+ (mapcar #'priority-map shared))) |