- 726 名前：723 mailto:sage [2007/07/04(水) 14:30:40 ]
- named-letでもやってみたんだけど、いまいち自信がないというか…。
(define (exclude-nth n ls)
(let loop ((ls ls) (n n) (acc '()))
(cond ((null? ls) (reverse! acc))
((= n 0) (if (not (pair? ls))
(reverse! acc)
(loop (cdr ls) (- n 1) acc)))
((not (pair? ls)) (append (reverse! acc) ls))
(else (loop (cdr ls) (- n 1) (cons (car ls) acc))))))
