Language: C C++ D Haskell Lua OCaml PHP Perl Plain Text Python Ruby Scheme Tcl ; swap list nodes (define (swap-kth-nodes xs k) (let loop1 ((a xs) (b xs) (k (- k 1))) (if (null? a) xs (if (positive? k) (loop1 (cdr a) (cdr b) (- k 1)) (let loop2 ((b b) (c xs)) (if (pair? (cdr b)) (loop2 (cdr b) (cdr c)) (if (eq? a c) xs (let ((t (car a))) (set-car! a (car c)) (set-car! c t) xs)))))))) (display (swap-kth-nodes '() 3)) (newline) (display (swap-kth-nodes '(1) 3)) (newline) (display (swap-kth-nodes '(1 2) 3)) (newline) (display (swap-kth-nodes '(1 2 3) 3)) (newline) (display (swap-kth-nodes '(1 2 3 4) 3)) (newline) (display (swap-kth-nodes '(1 2 3 4 5) 3)) (newline) (display (swap-kth-nodes '(1 2 3 4 5 6) 3)) (newline) (display (swap-kth-nodes '(1 2 3 4 5 6 7) 3)) (newline) (display (swap-kth-nodes '(1 2 3 4 5 6 7 8) 3)) (newline) (display (swap-kth-nodes '(1 2 3 4 5 6 7 8 9) 3)) (newline) Private [?] Run code Submit