exercise-13.scm (280B)
1 (define-library (sicp solutions chapter-3 exercise-13) 2 (import (scheme base)) 3 (export make-cycle) 4 5 (begin 6 (define (last-pair x) 7 (if (null? (cdr x)) 8 x 9 (last-pair (cdr x)))) 10 11 (define (make-cycle x) 12 (set-cdr! (last-pair x) x) 13 x)))