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> (occurrences '(a b a d a c d c a))((A . 4) (C . 2) (D . 2) (B . 1))
| (defun cnt-item (item lst) (let (( cnt 0)) (dolist (obj lst) (if (equal obj item) (setf cnt (+ cnt 1)))) (cons item cnt)))CL-USER> (cnt-item 'a '(a b c a))(A . 2)CL-USER> (defun occ (lst) (if (null lst) nil (let ((x nil)) (dolist (obj lst) (pushnew (cnt-item obj lst) x ))x)))STYLE-WARNING: redefining COMMON-LISP-USER::OCC in DEFUNOCCCL-USER> (occ '(a b b a c))((C . 1) (A . 2) (B . 2) (B . 2) (A . 2))CL-USER> (defun occ (lst) (if (null lst) nil (let ((x nil)) (dolist (obj lst) (pushnew (cnt-item obj lst) x :test #'equal ))x)))STYLE-WARNING: redefining COMMON-LISP-USER::OCC in DEFUNOCCCL-USER> (occ '(a b b a c))((C . 1) (B . 2) (A . 2))CL-USER> CL-USER> (occ '(a a b b c c (a.c) b b a c))(((A.C) . 1) (C . 3) (B . 4) (A . 3))CL-USER> |
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