Initial data commit

Task/Sorting-algorithms-Quicksort/Common-Lisp/sorting-algorithms-quicksort-1.lisp

@@ -0,0 +1,6 @@
+(defun quicksort (list &aux (pivot (car list)) )
+  (if (cdr list)
+      (nconc (quicksort (remove-if-not #'(lambda (x) (< x pivot)) list))
+             (remove-if-not #'(lambda (x) (= x pivot)) list)
+             (quicksort (remove-if-not #'(lambda (x) (> x pivot)) list)))
+      list))

Task/Sorting-algorithms-Quicksort/Common-Lisp/sorting-algorithms-quicksort-2.lisp

@@ -0,0 +1,6 @@
+(defun qs (list)
+  (if (cdr list)
+      (flet ((pivot (test)
+               (remove (car list) list :test-not test)))
+        (nconc (qs (pivot #'>)) (pivot #'=) (qs (pivot #'<))))
+      list))

Task/Sorting-algorithms-Quicksort/Common-Lisp/sorting-algorithms-quicksort-3.lisp

@@ -0,0 +1,14 @@
+(defun quicksort (sequence)
+  (labels ((swap (a b) (rotatef (elt sequence a) (elt sequence b)))
+           (sub-sort (left right)
+             (when (< left right)
+               (let ((pivot (elt sequence right))
+                     (index left))
+                 (loop for i from left below right
+                       when (<= (elt sequence i) pivot)
+                         do (swap i (prog1 index (incf index))))
+                 (swap right index)
+                 (sub-sort left (1- index))
+                 (sub-sort (1+ index) right)))))
+    (sub-sort 0 (1- (length sequence)))
+    sequence))

Task/Sorting-algorithms-Quicksort/Common-Lisp/sorting-algorithms-quicksort-4.lisp

@@ -0,0 +1,6 @@
+(defun quicksort (list)
+  (when list
+    (destructuring-bind (x . xs) list
+      (nconc (quicksort (remove-if (lambda (a) (> a x)) xs))
+	     `(,x)
+	     (quicksort (remove-if (lambda (a) (<= a x)) xs))))))