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  1. Prepare
  2. Functional Programming
  3. Recursion
  4. String Compression
  5. Discussions

String Compression

  • meriororen
     + 0 comments

    Racket. It's a little bit unfriendly for racket to process strings I think. 

    #lang racket
(define (num-to-list-of-char x)
  (string->list (number->string x)))

(define (compress l [c 1])
  (if (empty? (cdr l))
      (cons (car l) (if (= 1 c) (list) (num-to-list-of-char c)))
      (if (char=? (car l) (cadr l))
          (compress (cdr l) (+ c 1))
          (if (> c 1)
              (cons (car l) (append (num-to-list-of-char c) (compress (cdr l))))
              (cons (car l) (compress (cdr l)))))))

(let ([q (read-line)])
  (display (list->string (compress (string->list q)))))