39 lines
1.4 KiB
Common Lisp
39 lines
1.4 KiB
Common Lisp
(defun ten-to-bin (x)
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"Преобразует число в список бит"
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(let ((bin '()))
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(loop while (/= 0 x) do
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(multiple-value-bind (quotient remainder) (truncate x 2)
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(setf x quotient)
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(push remainder bin)))
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bin))
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(defun calculate-sum (numbers mask)
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"Считает сумму элементов, соответствующих единицам в маске."
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(loop for num in numbers
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for flag in mask
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when (= flag 1)
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sum num))
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(defun find-sum (target numbers)
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"Перебирает все комбинации (через битовые маски) для поиска целевой суммы."
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(let* ((len (length numbers))
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(total-combinations (1- (expt 2 len))))
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(loop for index from 0 to total-combinations
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for mask = (ten-to-bin index)
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for current-sum = (calculate-sum numbers mask)
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do (when (= current-sum target)
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(format t "OK: ~A~%" mask)
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(return-from find-sum mask)))
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(progn
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(format t "NO: not found ~%")
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'())))
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(defun main (args)
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(let ((len (length args)))
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(if (or (< len 5) (> len 30))
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(progn
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(format t "ER: input parameters~%")
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(uiop:quit 1))
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(let ((target (parse-integer (first args)))
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(numbers (mapcar #'parse-integer (rest args))))
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(find-sum target numbers)))))
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