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Discussion on: Daily Coding Puzzles - Nov 4th - Nov 9th

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Replies for: Friday The Last Word (CodeJam): You are the next contestant on this show, and the host has just showed you the string S. What's the winning last...

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David Wickes •

Common Lisp

(defun last-word (word)
  (let ((cs (coerce word 'list)))
    (coerce (reduce #'(lambda (word c)
                        (if (char> (first word) c)
                            (append word (list c))
                            (cons c word)))
                    (rest cs)
                    :initial-value (list (first cs)))
            'string)))

Quick little test...

(mapcar #'last-word (list "CAB"
                          "JAM"
                          "CODE"
                          "ABAAB"
                          "CABCBBABC"
                          "ABCABCABC"
                          "ZXCASDQWE"))
;; => ("CAB" "MJA" "OCDE" "BBAAA" "CCCABBBAB" "CCCBAABAB" "ZXCASDQWE")