Sorting algorithms/Selection sort: Difference between revisions

<lang lisp>(defun selection-sort-vector (array predicate)

mindex j)))))

(defun selection-sort-list (list predicate)

(flet ((min-first (list)

(do ((before-min nil)

(min (first list))

(prev list (rest prev))

(curr (rest list) (rest curr)))

((endp curr)

(if (null before-min) list

(let ((min (cdr before-min)))

(rplacd before-min (cdr min))

(rplacd min list)

min)))

(when (funcall predicate (first curr) min)

(setf before-min prev

min (first curr))))))

(let ((result (min-first list)))

(do ((head result (rest head)))

((endp (rest head)) result)

(rplacd head (min-first (rest head)))))))

(defun selection-sort (sequence predicate)

(etypecase sequence

(list (selection-sort-list sequence predicate))

(vector (selection-sort-vector sequence predicate))))</lang>

Example use:

<pre>> (let ((l (list 8 7 4 3 2 0 9 1 5 6)))

(selection-sort l '<))

(0 1 2 3 4 5 6 7 8 9)

> (let ((l (vector 8 7 4 3 2 0 9 1 5 6)))

(selection-sort l '>))