(define c 262144) (define zufallszahlen (lambda (z) (let ((a 16807)(b 0)) (if (eq? z 0) 4567 (modulo (+ (* a (zufallszahlen (- z 1))) b) c)))))

(define select-random (lambda (ls) (let ((len (length ls))) (list-ref ls (random len))))) (define (quicksort L) (if (null? L) L (letrec ((pivot (select-random L)) (split (lambda (piv li return) (cond ((null? li) return) ((< (car li) piv) (split piv (cdr li) (cons (cons (car li) (car return)) (cdr return)))) (else (split piv (cdr li) (cons (car return) (cons (car li) (cdr return))))))) )) `(,@(quicksort (car (split pivot (cdr L) '(() . ())))) ,pivot ,@(quicksort (cdr (split pivot (cdr L) '(() . ()))))) ) ) )

3.2