Language: C C++ D Haskell Lua OCaml PHP Perl Plain Text Python Ruby Scheme Tcl ; crypt (define (crypt key infile outfile) (define (last-pair xs) (if (null? (cdr xs)) xs (last-pair (cdr xs)))) (define (cycle xs) (set-cdr! (last-pair xs) xs) xs) (with-input-from-file infile (lambda () (with-output-to-file outfile (lambda () (do ((key (cycle (map char->integer (string->list key))) (cdr key)) (char (read-char) (read-char))) ((eof-object? char)) (display (integer->char (logxor (car key) (char->integer char)))))))))) Private [?] Run code