lisp lang solution №1

lisp/solution1.lisp

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