100 doors: Difference between revisions

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(print-doors (do-all-visits doors size open shut))))</lang>

'''Unoptimized / imperative '''

'''Unoptimized, imperative '''

This is a version that closely follows the problem description and is still quite short.

This is a version that closely follows the problem description and is still quite short. Of all the presented solutions it might be closest to "idiomatic Common Lisp".

<lang lisp>(define-modify-macro toggle () not)

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(format t "door ~a: ~:[closed~;open~]~%" (1+ i) (svref doors i)))))</lang>

'''Optimized '''

'''Optimized'''

This is an optimized version of the above, using the perfect square algorithm ~~(Note: This is non-functional as the state of the doors variable gets modified by a function call)~~

This is an optimized version of the above, using the perfect square algorithm.

<lang-lisp>(defun 100-doors ()

(let ((doors (make-array 100 :initial-element nil)))

(dotimes (i 10)

(setf (svref doors (* i i)) t))

(dotimes (i 100)

(format t "door ~a: ~:[closed~;open~]~%" (1+ i) (svref doors i)))))</lang>

'''Optimized 2'''

Another optimized version, with finer granular separation of functionality (might be a bit excessive).

<lang lisp>(defun perfect-square-list (n)

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'''Optimized (2) '''

This version displays a much more functional solution through the use of MAPCAR ~~(note however that this is imperative as it does variable mutation)~~

This version displays a much more functional solution through the use of MAPCAR.

<lang lisp>(let ((i 0))